diff --git a/.gitignore b/.gitignore
index 955a6f2c97..71dd08e68a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -163,3 +163,8 @@ dmypy.json
 cython_debug/
 
 .*.swp
+
+# Claude specific files
+CLAUDE.md
+.rules/
+.context/
diff --git a/mkdocs.yml b/mkdocs.yml
index 28ba5d5b5a..dbcf0433cd 100644
--- a/mkdocs.yml
+++ b/mkdocs.yml
@@ -11,6 +11,7 @@ nav:
           - Phenotypic and assessment data: modality-agnostic-files/phenotypic-and-assessment-data.md
           - Code: modality-agnostic-files/code.md
           - Events: modality-agnostic-files/events.md
+          - Stimuli: modality-agnostic-files/stimuli.md
       - Modality specific files:
           - Magnetic Resonance Imaging: modality-specific-files/magnetic-resonance-imaging-data.md
           - Magnetoencephalography: modality-specific-files/magnetoencephalography.md
diff --git a/src/metaschema.json b/src/metaschema.json
index e5d4c7b400..b663e9ac74 100644
--- a/src/metaschema.json
+++ b/src/metaschema.json
@@ -393,7 +393,12 @@
                 "^[a-z]+$": {
                   "type": "object",
                   "patternProperties": {
-                    "^[a-zA-Z0-9_]+$": { "$ref": "#/definitions/suffixRule" }
+                    "^[a-zA-Z0-9_]+$": {
+                      "anyOf": [
+                        { "$ref": "#/definitions/suffixRule" },
+                        { "$ref": "#/definitions/stemRule" }
+                      ]
+                    }
                   },
                   "additionalProperties": false
                 }
@@ -689,7 +694,30 @@
           "items": { "type": "string", "pattern": "^[a-z]+$" }
         },
         "stem": { "type": "string" },
-        "extensions": { "type": "array", "items": { "type": "string" } }
+        "path": { "type": "string" },
+        "extensions": { "type": "array", "items": { "type": "string" } },
+        "entities": {
+          "type": "object",
+          "patternProperties": {
+            "^[a-z]+$": {
+              "anyOf": [
+                { "enum": ["optional", "required"] },
+                {
+                  "type": "object",
+                  "properties": {
+                    "level": { "enum": ["optional", "required"] },
+                    "enum": {
+                      "type": "array",
+                      "items": { "type": "string" }
+                    }
+                  },
+                  "required": ["level", "enum"]
+                }
+              ]
+            }
+          },
+          "additionalProperties": false
+        }
       },
       "required": ["level", "stem", "extensions"],
       "additionalProperties": false
@@ -707,6 +735,7 @@
           "type": "array",
           "items": { "type": "string", "pattern": "^[a-zA-Z0-9]+$" }
         },
+        "path": { "type": "string" },
         "extensions": { "type": "array", "items": { "type": "string" } },
         "entities": {
           "type": "object",
diff --git a/src/modality-agnostic-files/events.md b/src/modality-agnostic-files/events.md
index 1c65a0196e..f456824a2a 100644
--- a/src/modality-agnostic-files/events.md
+++ b/src/modality-agnostic-files/events.md
@@ -397,3 +397,35 @@ A guide for using macros can be found at
 Additional metadata may be included as in
 [any TSV file](../common-principles.md#tabular-files) to specify, for
 example, the units of the recorded time series for each column.
+
+## Stimulus Organization
+
+For standardized organization and reuse of stimulus files, events may reference stimuli using two approaches:
+
+### Using `stim_file`
+
+Reference stimulus files directly using the `stim_file` column, where values represent the relative path to the stimulus file within the `/stimuli` directory:
+
+```JSON
+{
+    "stim_file": {
+        "LongName": "Stimulus file",
+        "Description": "Location of stimulus file presented at the given onset time, relative to /stimuli directory."
+    }
+}
+```
+
+### Using `stim_id`
+
+Reference stimulus identifiers using the `stim_id` column to link events to comprehensive stimulus metadata and annotations:
+
+```JSON
+{
+    "stim_id": {
+        "LongName": "Stimulus identifier",
+        "Description": "Unique identifier linking to stimulus files and annotations in /stimuli directory."
+    }
+}
+```
+
+For detailed information on stimulus file organization, metadata, and annotations, see the [Stimuli](./stimuli.md) specification.
diff --git a/src/modality-agnostic-files/stimuli.md b/src/modality-agnostic-files/stimuli.md
new file mode 100644
index 0000000000..04b0a6b7ca
--- /dev/null
+++ b/src/modality-agnostic-files/stimuli.md
@@ -0,0 +1,160 @@
+# Stimuli
+
+## Stimulus Files Organization
+
+Stimulus files MUST be stored in the `/stimuli` directory under the root directory of the dataset.
+The `/stimuli` directory can contain subdirectories to organize the stimulus files.
+Stimulus files MUST follow the BIDS naming conventions and are referenced in the `events.tsv`
+file using the `stim_id` column.
+
+The standardization of stimulus files and their annotations within BIDS offers several key benefits:
+
+1.  **Consistency**: Ensures uniform storage and referencing across datasets
+1.  **Reusability**: Enables stimulus reuse across studies through standardized structure
+1.  **Efficiency**: Minimizes redundancy by centralizing annotations
+1.  **Flexibility**: Facilitates dataset reuse with alternative annotations
+
+To preserve backward compatibility with existing datasets (see the Legacy section below), the use of these specifications for the `/stimuli` directory and the `stim_id` column in the `events.tsv` files is RECOMMENDED but not required. Researchers are encouraged to follow these guidelines to enhance the interoperability and reproducibility of their studies.
+
+Following these guidelines will help ensure that stimulus files and their annotations are stored and referenced consistently across different datasets, facilitating data sharing, reuse, and reproducibility.
+
+## File Organization
+
+<!--
+This block generates a filename templates for root-level directories.
+The inputs for this macro can be found in the directory
+  src/schema/rules/files/raw
+and a guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_root_filename_template(
+   "raw",
+   path="stimuli")
+}}
+
+Note: The presence of the `stimuli.tsv` file indicates that the content of the `/stimuli` directory follows this BIDS specification for stimulus organization.
+
+### Stimulus File Formats
+
+The following table lists the supported stimulus file formats and their corresponding suffixes. The suffixes are used to identify the type of stimulus file and are appended to the `stim-<label>` prefix in the file name.
+
+| suffix      | extensions                      | description                  |
+| ----------- | ------------------------------- | ---------------------------- |
+| audio       | `.wav`, `.mp3`, `.aac`, `.ogg`  | Audio-only stimulus files    |
+| image       | `.jpg`, `.png`, `.svg`, `.webp` | Static visual stimulus files |
+| video       | `.mp4`, `.avi`, `.mkv`, `.webm` | Video-only stimulus files    |
+| audiovideo  | `.mp4`, `.avi`, `.mkv`, `.webm` | Combined audio-visual files  |
+
+## Stimulus description (`stim-<label>_<suffix>.json`)
+
+The `stim-<label>_<suffix>.json` file provides metadata about the _singular_ stimulus file.
+The following fields are defined to describe the stimulus file:
+
+<!-- This block generates a metadata table.
+These tables are defined in
+  src/schema/rules/sidecars
+The definitions of the fields specified in these tables may be found in
+  src/schema/objects/metadata.yaml
+A guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_sidecar_table("stimuli.Stimuli") }}
+
+In some cases, such as observing the copyright of a stimulus file, the actual stimulus file may not be shared. In such cases, the `stim-<label>_<suffix>.json` file SHOULD be used to provide metadata about the stimulus file, including the license, copyright, URL, and description.
+
+### Example `stim-<label>_<suffix>.json`
+
+```JSON
+{
+    "License": "CC-BY-4.0",
+    "Copyright": "2023 Lab Name lab@university.edu",
+    "URL": "https://example.com/stimuli/",
+    "Description": "Collection of face images, tones, and movie clips used in the experiment"
+}
+```
+
+The `License` field SHOULD provide the known identifiers, such as `PDL`, `CC0`, `CC-BY` from the [BIDS Licensees Appendix](https://bids-specification.readthedocs.io/en/stable/appendices/licenses.html), or common license lists such as [SPDX](https://spdx.org/licenses/) or [Creative Commons](https://creativecommons.org/licenses/).
+The `Copyright` filed SHOULD provide the year, copyright holder's name, and if available, the email address of the copyright holder.
+If the stimulus file is not shared, the `URL` field SHOULD provide a link to the stimulus file.
+
+## Stimuli Description (`stimuli.tsv`)
+
+The `stimuli.tsv` files are used to provide information about the stimuli based on their `stim_id`. This file is similar in usage as `participants.tsv`, `scans.tsv` and `sessions.tsv`, which list descriptions about subjects, scans and sessions, respectively. The `stimuli.tsv` files MUST be placed in the `/stimuli` directory.
+
+The `stimuli.tsv` file contains information about each stimulus, including stimulus ID, type, URL, and other relevant details. The following table describes the REQUIRED, RECOMMENDED, and OPTIONAL columns for the `stimuli.tsv` file:
+
+<!-- This block generates a columns table.
+The definitions of these fields can be found in
+  src/schema/rules/tabular_data/*.yaml
+and a guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_columns_table("stimuli.Stimuli") }}
+
+### Example `stimuli.tsv`
+
+```Text
+stimulus_id    type     URL                                     license      copyright    description                                  present
+stim-face01   image    https://example.com/faces/face01.jpg    CC-BY-4.0   Lab 2023    A female face with neutral expression       true
+stim-tone01   audio    https://example.com/tones/tone01.wav    CC-BY-4.0   Lab 2023    A 440Hz pure tone                          true
+stim-movie01  video    https://example.com/movies/movie01.mp4  n/a         Studio XYZ  A clip from copyrighted movie              false
+```
+
+The `stimuli.json` file provides detailed descriptions of the columns in the `stimuli.tsv` file. There MAY be extra entries in the `stimuli.json` in addition to the columns in the `stimuli.tsv` to provide more details about the stimulus.
+
+In cases where the stimulus is not shared, the `stimuli.tsv` file can be used to provide metadata about the stimuli, including the license, copyright, URL, and description. This is similar to the use of `stim-<label>_<suffix>.json` files for individual stimuli files. In the case of conflict between the metadata in the `stimuli.tsv` and `stim-<label>_<suffix>.json` files, the metadata in the `stim-<label>_<suffix>.json` file takes precedence.
+
+## Stimulus Annotations
+
+Annotations of the still images or general description of the stimuli (such as frequency and duration of a beep sound) can be stored in the `stimuli.tsv` as an additional column or `stim-<label>_<suffix>.json` as described above. Here is an example of how annotations can be stored in the `stimuli.tsv` file for an image from the Natural Scene Dataset (NSD):
+
+| stimulus_id   | type  | description                                           | HED                                                                                                                                                               | NSD_id | COCO_id |
+| ------------- | ----- | ----------------------------------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------ | ------- |
+| stim-nsd02951 | image | an open market full of people and piles of vegetables | ((Item-count, High), Ingestible-object), (Background-view, ((Human, Body, Agent-trait/Adult), Outdoors, Furnishing, Natural-feature/Sky, Urban, Man-made-object)) | 2951   | 262145  |
+
+However, for time-varying stimuli, such as audio or video, it is RECOMMENDED to use specific annotations files in the form of `stim-<label>_annot-<label>_events.tsv` to store the annotations. These files have the same structure as the `events.tsv` files and are used to store annotations for the stimuli. There can be multiple annotation files for a single stimulus file, each with a unique annotation label. The annotation files MUST be stored in the `/stimuli` directory.
+
+## Annotation Description (`annotations.tsv`)
+
+The `annotations.tsv` file contains additional metadata about stimulus annotations. There MAY be a single `annotations.tsv` file for all the stimuli or separate `stim-<label>_annotations.tsv` files for each stimulus.
+The following columns are defined for the `annotations.tsv` file:
+
+<!-- This block generates a columns table.
+The definitions of these fields can be found in
+  src/schema/rules/tabular_data/*.yaml
+and a guide for using macros can be found at
+ https://github.com/bids-standard/bids-specification/blob/master/macros_doc.md
+-->
+{{ MACROS___make_columns_table("stimuli.Annotations") }}
+
+### Example `*_annotations.tsv`
+
+```Text
+annot_id     description
+face01_emo   Emotion annotation for face01 stimulus
+face01_gen   Gender annotation for face01 stimulus
+face01_age   Age group annotation for face01 stimulus
+```
+
+## Referencing Stimulus Identifiers in `events.tsv`
+
+To reference stimulus identifiers in the `events.tsv` file, use the `stim_id` column. The values in the `stim_id` column should represent unique identifiers for the stimuli. Stimulus ID (`stim_id`) should correspond to the unique identifier of the stimulus file in the /stimuli directory and expand to all files (both stimulus and annotation files) that share the same stimulus ID.
+
+Example `events.tsv` file:
+
+| onset | duration | trial_type | response_time | stim_id        |
+| ----- | -------- | ---------- | ------------- | -------------- |
+| 1.23  | 0.65     | start      | 1.435         | `stim-<label>` |
+| 5.65  | 0.65     | stop       | 1.739         | `stim-<label>` |
+| 12.1  | 2.35     | n/a        | n/a           | `stim-<label>` |
+
+In the accompanying JSON sidecar, the `stim_id` column might be described as follows:
+
+```JSON
+{
+    "stim_id": {
+        "LongName": "Stimulus identifier",
+        "Description": "Represents a unique identifier for the stimulus presented at the given onset time."
+    }
+}
+```
diff --git a/src/modality-specific-files/behavioral-experiments.md b/src/modality-specific-files/behavioral-experiments.md
index b077fd4b85..0f74361093 100644
--- a/src/modality-specific-files/behavioral-experiments.md
+++ b/src/modality-specific-files/behavioral-experiments.md
@@ -25,6 +25,8 @@ metadata (`_events.json`),
 physiological (`_physio.tsv.gz`, `_physio.json`)
 and other continuous recordings (`_stim.tsv.gz`, `_stim.json`)
 as for tasks performed during MRI, electrophysiological or other neural recordings.
+
+Note that `*_stim.tsv.gz` files contain subject-specific, continuously-sampled stimulus-related signals (such as audio waveforms, video parameters, electrical, mechanical, or optical stimuli), which is distinct from subject-invariant stimulus files stored in the [`/stimuli` directory](../modality-agnostic-files/stimuli.md).
 Additionally, events files
 that do not include the mandatory `onset` and `duration` columns
 MAY be included,
diff --git a/src/schema/objects/columns.yaml b/src/schema/objects/columns.yaml
index f5422abab2..7275f931b1 100644
--- a/src/schema/objects/columns.yaml
+++ b/src/schema/objects/columns.yaml
@@ -589,6 +589,15 @@ stim_file:
     For example `images/cat03.jpg` will be translated to `/stimuli/images/cat03.jpg`.
   type: string
   format: stimuli_relative
+stim_id:
+  name: stim_id
+  display_name: Stimulus identifier
+  description: |
+    Represents a unique identifier for the stimulus presented at the given onset
+    time. The `stim_id` is inclusive of the stimulus file(s), annotations
+    related to the stimulus, and the information about the stimulus present in
+    the `stimuli.tsv` file.
+  type: string
 strain:
   name: strain
   display_name: Strain
@@ -852,3 +861,69 @@ template_z:
   description: |
     Assumed or ideal position along the z axis.
   type: number
+stimulus_id:
+  name: stimulus_id
+  display_name: Stimulus Identifier
+  description: |
+    Unique identifier for a specific stimulus.
+  type: string
+annot_id:
+  name: annot_id
+  display_name: Annotation Identifier
+  description: |
+    Unique identifier for a specific annotation set applying to a stimulus or group of stimuli. Links to annotation
+    files (for example, `*_annot-<label>_events.tsv`).
+  type: string
+copyright:
+  name: copyright
+  display_name: Stimulus Copyright
+  description: |
+    Copyright information for the stimulus file, typically including year and holder.
+  type: string
+license:
+  name: license
+  display_name: Stimulus License
+  description: |
+    License under which the stimulus file is distributed.
+    SHOULD use identifiers from recognized lists like SPDX or Creative Commons.
+  type: string
+partDescription__stimuli:
+  name: partDescription
+  display_name: Stimulus Part Description
+  description: |
+    Free-form text description of a specific part of a stimulus, relevant when the stimulus is split into multiple
+    files using the `part` entity.
+  type: string
+present:
+  name: present
+  display_name: Stimulus File Present
+  description: |
+    Indicates whether the stimulus file corresponding to the `stimulus_id` is physically present in the dataset.
+  type: boolean
+URL:
+  name: URL
+  display_name: Stimulus URL
+  description: |
+    Uniform Resource Locator pointing to the stimulus file, particularly useful
+    if the stimulus file is not distributed with the dataset.
+  type: string
+  format: uri
+description__stimuli:
+  name: description
+  display_name: Stimulus Description
+  description: |
+    Free-form text description of the stimulus identified by `stimulus_id`.
+  type: string
+description__annot:
+  name: description
+  display_name: Annotation Description
+  description: |
+    Free-form text description of the annotation identified by `annot_id`.
+  type: string
+type__stimuli:
+  name: type
+  display_name: Stimulus type
+  description: |
+    Type of stimulus (for example, image, audio, video).
+    Refers to the suffix of the stimulus file if present.
+  type: string
diff --git a/src/schema/objects/datatypes.yaml b/src/schema/objects/datatypes.yaml
index 333cc4d922..c8e17499ca 100644
--- a/src/schema/objects/datatypes.yaml
+++ b/src/schema/objects/datatypes.yaml
@@ -72,3 +72,8 @@ nirs:
   value: nirs
   display_name: Near-Infrared Spectroscopy
   description: Near-Infrared Spectroscopy data organized around the SNIRF format
+stimuli:
+  value: stimuli
+  display_name: Stimuli
+  description: |
+    Stimulus data, including audio, video, images, and annotations.
diff --git a/src/schema/objects/entities.yaml b/src/schema/objects/entities.yaml
index be94a5eb0a..0d03506059 100644
--- a/src/schema/objects/entities.yaml
+++ b/src/schema/objects/entities.yaml
@@ -224,6 +224,10 @@ part:
 
     When there is only a magnitude image of a given type, the `part` entity MAY be
     omitted.
+
+    For stimulus files, `part-<label>` can be used to distinguish different parts of a single stimulus, such as
+    chapters in an audiobook or segments of a long movie (for example, `part-1`, `part-2`, `part-epilog`,
+    `part-chapter1`).
   type: string
   format: label
   enum:
@@ -231,6 +235,14 @@ part:
     - $ref: objects.enums.phase.value
     - $ref: objects.enums.real.value
     - $ref: objects.enums.imaginary.value
+part__stimuli:
+  name: part
+  display_name: Stimulus Part
+  description: |
+    For stimulus files, `part-<label>` can be used to distinguish different parts of a single stimulus,
+    such as chapters in an audiobook or segments of a long movie (for example, `part-1`, `part-2`, `part-epilog`).
+  type: string
+  format: label
 processing:
   name: proc
   display_name: Processed (on device)
@@ -393,6 +405,19 @@ stain:
     and/or `"SampleSecondaryAntibodies"` metadata fields, as appropriate.
   type: string
   format: label
+stimulus:
+  name: stim
+  display_name: Stimulus
+  description: |
+    The `stim-<label>` entity can be used to distinguish different stimulus files
+    or annotations. The label is a unique identifier for the stimulus or annotation.
+
+    This entity represents the `"Stimulus"` metadata field and requires corresponding
+    entries in the `stimuli.tsv` file. Therefore, if the `stim-<label>` entity is
+    present in a filename, `"Stimulus"` MUST be defined in the associated metadata,
+    and a matching entry MUST exist in the `stimuli.tsv` file.
+  type: string
+  format: label
 subject:
   name: sub
   display_name: Subject
@@ -463,3 +488,13 @@ tracksys:
     may be longer and more human readable.
   type: string
   format: label
+annotation:
+  name: annot
+  display_name: Annotation
+  description: |
+    The `annot-<label>` entity accommodates multiple annotations for a single
+    (usually, but not necessarily, time-varying) stimulus id. Similar to `stimuli.tsv`,
+    there can be one or multiple `annotations.tsv` files with `annotation_id`, providing
+    a list of the annotations in the directory, or for a specific stimulus respectively.
+  type: string
+  format: label
diff --git a/src/schema/objects/extensions.yaml b/src/schema/objects/extensions.yaml
index d482f8849d..b5b6c6cca2 100644
--- a/src/schema/objects/extensions.yaml
+++ b/src/schema/objects/extensions.yaml
@@ -293,6 +293,61 @@ txt:
     A free-form text file.
 
     Tab-delimited files should have the `.tsv` extension rather than a `.txt` extension.
+wav:
+  value: .wav
+  display_name: Waveform Audio File Format
+  description: |
+    A digital audio file format.
+mp3:
+  value: .mp3
+  display_name: MPEG Audio Layer III
+  description: |
+    A digital audio file format.
+aac:
+  value: .aac
+  display_name: Advanced Audio Coding
+  description: |
+    A digital audio file format.
+ogg:
+  value: .ogg
+  display_name: Ogg Vorbis
+  description: |
+    A digital audio file format.
+svg:
+  value: .svg
+  display_name: Scalable Vector Graphics
+  description: |
+    A vector graphics file format.
+webp:
+  value: .webp
+  display_name: WebP
+  description: |
+    A modern image file format.
+tiff:
+  value: .tiff
+  display_name: Tagged Image File Format
+  description: |
+    A raster graphics file format.
+mp4:
+  value: .mp4
+  display_name: MPEG-4 Part 14
+  description: |
+    A digital video file format.
+avi:
+  value: .avi
+  display_name: Audio Video Interleave
+  description: |
+    A digital video file format.
+mkv:
+  value: .mkv
+  display_name: Matroska Video
+  description: |
+    A digital video file format.
+webm:
+  value: .webm
+  display_name: WebM
+  description: |
+    A digital video file format.
 vhdr:
   value: .vhdr
   display_name: BrainVision Text Header
diff --git a/src/schema/objects/metadata.yaml b/src/schema/objects/metadata.yaml
index 5540049f96..e5508bbfda 100644
--- a/src/schema/objects/metadata.yaml
+++ b/src/schema/objects/metadata.yaml
@@ -615,6 +615,11 @@ ContrastBolusIngredient:
     # TODO: Add definitions for these values. (perhaps don't specify)
     - UNKNOWN
     - NONE
+Copyright:
+  name: Copyright
+  display_name: Copyright
+  description: Copyright information
+  type: string
 DCOffsetCorrection:
   name: DCOffsetCorrection
   display_name: DC Offset Correction
@@ -1995,6 +2000,11 @@ License:
     The corresponding full license text MAY be specified in an additional
     `LICENSE` file.
   type: string
+StimulusLicense:
+  name: License
+  display_name: License
+  description: License under which this stimulus is shared.
+  type: string
 LongName:
   name: LongName
   display_name: Long Name
@@ -3789,6 +3799,11 @@ SubjectArtefactDescription:
     If this field is set to `"n/a"`, it will be interpreted as absence of major
     source of artifacts except cardiac and blinks.
   type: string
+StimulusURL:
+  name: URL
+  display_name: URL
+  description: Location (origin) for the stimulus file.
+  type: string
 TablePosition:
   name: TablePosition
   display_name: Table Position
@@ -4196,3 +4211,10 @@ iEEGReference:
     this field should have a general description and the channel specific
     reference should be defined in the `channels.tsv` file.
   type: string
+type:
+  name: type
+  display_name: Type
+  description: |
+    Type of stimulus file (for example, image, audio, video, audiovideo).
+    Refers to the suffix of the stimulus file when present in stimulus metadata.
+  type: string
diff --git a/src/schema/objects/suffixes.yaml b/src/schema/objects/suffixes.yaml
index 1e2825ced2..52e007800c 100644
--- a/src/schema/objects/suffixes.yaml
+++ b/src/schema/objects/suffixes.yaml
@@ -877,3 +877,40 @@ unloc:
   description: |
     MRS acquisitions run without localization.
     This includes signals detected using coil sensitivity only.
+audio:
+  value: audio
+  display_name: Audio stimulus file
+  description: |
+    Any data file used as an audio stimulus. Media files usually have an audio file type (such as wav, mp3, aac, ogg).
+    The JSON sidecar associated with each media file should contain information to describe the origin and the
+    nature of the media.
+    However, in the case of the imposed distribution restrictions of the stimulus, the media stimulus file may not be
+    present with only JSON sidecar file containing the aforementioned pertinent metadata.
+image:
+  value: image
+  display_name: Image stimulus file
+  description: |
+    Any data file used as an image stimulus. Media files usually have an image file type (such as jpg, png, svg).
+    The JSON sidecar associated with each media file should contain information to describe the origin and the
+    nature of the media.
+    However, in the case of the imposed distribution restrictions of the stimulus, the media stimulus file may not be
+    present with only JSON sidecar file containing the aforementioned pertinent metadata.
+video:
+  value: video
+  display_name: Video stimulus file
+  description: |
+    Any data file used as a video stimulus. Media files usually have a video file type (such as mp4, avi, mkv, webm).
+    The JSON sidecar associated with each media file should contain information to describe the origin and the
+    nature of the media.
+    However, in the case of the imposed distribution restrictions of the stimulus, the media stimulus file may not be
+    present with only JSON sidecar file containing the aforementioned pertinent metadata.
+audiovideo:
+  value: audiovideo
+  display_name: Audiovideo stimulus file
+  description: |
+    Any data file used as an audiovideo stimulus. Media files usually have an audiovideo file type (such as mp4, avi,
+    mkv, webm).
+    The JSON sidecar associated with each media file should contain information to describe the origin and the
+    nature of the media.
+    However, in the case of the imposed distribution restrictions of the stimulus, the media stimulus file may not be
+    present with only JSON sidecar file containing the aforementioned pertinent metadata.
diff --git a/src/schema/rules/checks/events.yaml b/src/schema/rules/checks/events.yaml
index 6d884a0ee8..fd17d8a682 100644
--- a/src/schema/rules/checks/events.yaml
+++ b/src/schema/rules/checks/events.yaml
@@ -31,6 +31,18 @@ StimulusFileMissing:
   checks:
     - exists(columns.stim_file, "stimuli") == length(columns.stim_file) - count(columns.stim_file, "n/a")
 
+StimulusIDMissing:
+  issue:
+    code: STIMULUS_ID_MISSING
+    message: |
+      A stimulus identifier was declared but not found in the dataset.
+    level: error
+  selectors:
+    - intersects([suffix], ["events", "beh"])
+    - columns.stim_id != null
+  checks:
+    - exists(columns.stim_id, "stimuli") == length(columns.stim_id) - count(columns.stim_id, "n/a")
+
 SortedOnsets:
   issue:
     code: EVENT_ONSET_ORDER
diff --git a/src/schema/rules/checks/stimuli.yaml b/src/schema/rules/checks/stimuli.yaml
new file mode 100644
index 0000000000..bcb34f80db
--- /dev/null
+++ b/src/schema/rules/checks/stimuli.yaml
@@ -0,0 +1,38 @@
+---
+StimulusIdExists:
+  issue:
+    code: STIMULUS_ID_NOT_FOUND
+    message: |
+      Stimulus ID referenced in events.tsv file does not exist in the /stimuli directory
+      or is not properly referenced in stimuli.tsv file.
+    level: error
+  selectors:
+    - suffix == "events"
+    - '"stim_id" in columns'
+  checks:
+    - exists(columns.stim_id, "stimuli") == length(columns.stim_id) - count(columns.stim_id, "n/a")
+
+StimuliDirectoryStructure:
+  issue:
+    code: INVALID_STIMULUS_FILENAME
+    message: |
+      Stimulus files in the /stimuli directory must follow the BIDS naming convention
+      with the format stim-<label>[_part-<label>]_<suffix>.<extension>
+    level: warning
+  selectors:
+    - datatype == "stimuli"
+    - suffix in ["audio", "video", "audiovideo", "image"]
+  checks:
+    - entities.stimulus != null
+
+StimuliTableEntriesValid:
+  issue:
+    code: STIMULI_TABLE_REFERENCES
+    message: |
+      Each stimulus_id in stimuli.tsv must correspond to an actual stimulus file
+      in the /stimuli directory.
+    level: warning
+  selectors:
+    - suffix == "stimuli"
+  checks:
+    - matches_pattern(columns.stimulus_id, "^stim-[a-zA-Z0-9]+$")
diff --git a/src/schema/rules/directories.yaml b/src/schema/rules/directories.yaml
index e5415e8c14..940e6cad45 100644
--- a/src/schema/rules/directories.yaml
+++ b/src/schema/rules/directories.yaml
@@ -83,7 +83,7 @@ raw:
   stimuli:
     name: stimuli
     level: optional
-    opaque: true
+    opaque: false
   subject:
     entity: subject
     level: required
@@ -141,7 +141,7 @@ derivative:
   stimuli:
     name: stimuli
     level: optional
-    opaque: true
+    opaque: false
   subject:
     entity: subject
     level: optional
diff --git a/src/schema/rules/files/raw/stimuli.yaml b/src/schema/rules/files/raw/stimuli.yaml
new file mode 100644
index 0000000000..9d1d8336f0
--- /dev/null
+++ b/src/schema/rules/files/raw/stimuli.yaml
@@ -0,0 +1,94 @@
+---
+# Define the stimuli files (root-level directory, not subject-scoped)
+stimuli_table:
+  level: recommended
+  path: stimuli
+  stem: stimuli
+  extensions:
+    - .json
+    - .tsv
+  entities: {} # No entities apply to the stimuli.tsv/json index files themselves
+
+annotations_table:
+  level: recommended
+  path: stimuli
+  stem: annotations
+  extensions:
+    - .json
+    - .tsv
+  entities:
+    stimulus: optional # The annotations table can be global or stimulus-specific
+
+stimulus_audio:
+  level: optional
+  path: stimuli
+  suffixes:
+    - audio
+  extensions:
+    - .json
+    - .wav
+    - .mp3
+    - .aac
+    - .ogg
+  entities:
+    stimulus: required
+    part: optional
+
+stimulus_image:
+  level: optional
+  path: stimuli
+  suffixes:
+    - image
+  extensions:
+    - .json
+    - .jpg
+    - .png
+    - .svg
+    - .webp
+    - .tiff
+  entities:
+    stimulus: required
+    part: optional
+
+stimulus_video:
+  level: optional
+  path: stimuli
+  suffixes:
+    - video
+  extensions:
+    - .json
+    - .mp4
+    - .avi
+    - .mkv
+    - .webm
+  entities:
+    stimulus: required
+    part: optional
+
+stimulus_audiovideo:
+  level: optional
+  path: stimuli
+  suffixes:
+    - audiovideo
+  extensions:
+    - .json
+    - .mp4
+    - .avi
+    - .mkv
+    - .webm
+  entities:
+    stimulus: required
+    part: optional
+
+stimulus_annotations_events: # Renamed for clarity, representing the annot-<label>_events files
+  level: optional
+  path: stimuli
+  suffixes:
+    - events
+  extensions:
+    - .json
+    - .tsv
+  entities:
+    stimulus: required
+    annotation: required
+    part: optional
diff --git a/src/schema/rules/sidecars/stimuli.yaml b/src/schema/rules/sidecars/stimuli.yaml
new file mode 100644
index 0000000000..bb9305ab9e
--- /dev/null
+++ b/src/schema/rules/sidecars/stimuli.yaml
@@ -0,0 +1,12 @@
+---
+# Sidecar tables for stim-<label>_suffix.json, the stimuli.json and annotations.json do not need additional fields
+# as the fields have been already defined in the tabular data
+
+Stimuli:
+  selectors:
+    - intersects([suffix], ["audio", "video", "audiovideo", "image"])
+  fields:
+    StimulusLicense: recommended
+    Copyright: recommended
+    StimulusURL: optional
+    Description: optional
diff --git a/src/schema/rules/tabular_data/events.yaml b/src/schema/rules/tabular_data/events.yaml
index 5bf86123c1..625a3df15c 100644
--- a/src/schema/rules/tabular_data/events.yaml
+++ b/src/schema/rules/tabular_data/events.yaml
@@ -9,6 +9,7 @@ Events:
     response_time: optional
     HED: optional
     stim_file: optional
+    stim_id: optional
     channel:
       level: optional
       description_addendum: |
diff --git a/src/schema/rules/tabular_data/stimuli.yaml b/src/schema/rules/tabular_data/stimuli.yaml
new file mode 100644
index 0000000000..80e8240538
--- /dev/null
+++ b/src/schema/rules/tabular_data/stimuli.yaml
@@ -0,0 +1,42 @@
+---
+Stimuli:
+  selectors:
+    - suffix == "stimuli"
+  initial_columns:
+    - stimulus_id
+    - type
+  columns:
+    stimulus_id: required
+    type__stimuli: required
+    URL: optional
+    license: recommended
+    copyright: recommended
+    description__stimuli: recommended
+    HED: optional
+    filename: optional
+    present: optional
+    partDescription__stimuli: optional
+  additional_columns: allowed_if_defined
+
+Annotations:
+  selectors:
+    - suffix == "annotations"
+  initial_columns:
+    - annot_id
+    - description
+  columns:
+    annot_id: required
+    description__annot: required
+  additional_columns: allowed_if_defined
+
+StimulusEvents:
+  selectors:
+    - suffix == "events"
+    - entities.stimulus != null
+  initial_columns:
+    - onset
+    - duration
+  columns:
+    onset: required
+    duration: recommended
+  additional_columns: allowed_if_defined
diff --git a/tools/mkdocs_macros_bids/macros.py b/tools/mkdocs_macros_bids/macros.py
index 2e7c2f893e..8eff398e56 100644
--- a/tools/mkdocs_macros_bids/macros.py
+++ b/tools/mkdocs_macros_bids/macros.py
@@ -101,6 +101,119 @@ def make_filename_template(dstype="raw", src_path=None, pdf_format=False, **kwar
     return codeblock
 
 
+def make_root_filename_template(
+    dstype="raw", src_path=None, pdf_format=False, **kwargs
+):
+    """Generate a filename template snippet for root-level directories.
+
+    This function is designed for root-level directories like /stimuli
+    that use stem files and path-based organization (not subject-scoped datatypes).
+    """
+    if src_path is None:
+        src_path = _get_source_path()
+
+    # Load schema with explicit path to avoid caching issues
+    import os
+
+    schema_path = os.path.join(
+        os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
+        "src",
+        "schema.json",
+    )
+    if os.path.exists(schema_path):
+        schema_obj = schema.load_schema(schema_path)
+    else:
+        schema_obj = schema.load_schema()
+
+    # Look for rules that have a specific path (root-level organization)
+    target_path = kwargs.get("path", "stimuli")  # Default to stimuli
+
+    rules = schema_obj.rules.files[dstype]
+
+    # Find rules that match our target path (handle nested namespaces)
+    matching_rules = {}
+    for rule_name, rule in rules.items():
+        # Check if rule directly has the path
+        if hasattr(rule, "path") and rule.path == target_path:
+            matching_rules[rule_name] = rule
+        # Check if rule is a namespace containing rules with the path
+        elif not hasattr(rule, "path") and hasattr(rule, "keys"):
+            for sub_name in rule.keys():
+                sub_rule = rule[sub_name]
+                if hasattr(sub_rule, "path") and sub_rule.path == target_path:
+                    matching_rules[f"{rule_name}.{sub_name}"] = sub_rule
+
+    if not matching_rules:
+        return ""
+
+    # Generate template content
+    template_lines = [f"{target_path}/"]
+
+    # Process each matching rule
+    for rule_name, rule in matching_rules.items():
+        if hasattr(rule, "stem"):
+            # Handle stem-based files (like stimuli.tsv, annotations.tsv)
+            if hasattr(rule, "extensions"):
+                # For stem files, always show each extension explicitly
+                # These are important catalog files that should be clear
+                for ext in rule.extensions:
+                    template_lines.append(f"    {rule.stem}{ext}")
+
+        elif hasattr(rule, "suffixes"):
+            # Handle entity-based files generically using entity definitions from schema
+            entities_part = ""
+            if hasattr(rule, "entities"):
+                entity_parts = []
+                for entity_name, requirement in rule.entities.items():
+                    # Look up the entity in the schema to get its prefix and format
+                    if entity_name in schema_obj.objects.entities:
+                        entity_def = schema_obj.objects.entities[entity_name]
+                        entity_prefix = entity_def.get("name", entity_name)
+                        entity_format = entity_def.get("format", "label")
+
+                        # Format based on requirement (required vs optional)
+                        if requirement == "optional":
+                            entity_parts.append(f"[_{entity_prefix}-<{entity_format}>]")
+                        else:
+                            # First entity doesn't need underscore prefix
+                            if not entity_parts:
+                                entity_parts.append(
+                                    f"{entity_prefix}-<{entity_format}>"
+                                )
+                            else:
+                                entity_parts.append(
+                                    f"_{entity_prefix}-<{entity_format}>"
+                                )
+                entities_part = "".join(entity_parts)
+
+            for suffix in rule.suffixes:
+                if hasattr(rule, "extensions"):
+                    # Consolidate only when there are more than 2 extensions
+                    if len(rule.extensions) > 2:
+                        # Show the pattern once with generic extension
+                        # Need to escape < and > for HTML but not for PDF
+                        ext_placeholder = (
+                            "<extension>" if pdf_format else "&lt;extension&gt;"
+                        )
+                        template_lines.append(
+                            f"    {entities_part}_{suffix}.{ext_placeholder}"
+                        )
+                    else:
+                        # Show each extension explicitly for clarity
+                        for ext in rule.extensions:
+                            template_lines.append(f"    {entities_part}_{suffix}{ext}")
+
+    # Format as code block
+    template_content = "\n".join(template_lines)
+
+    if pdf_format:
+        return f"```Text\n{template_content}\n```"
+    else:
+        return (
+            f'<div class="highlight"><pre><code>{template_content}</code></pre></div>'
+        )
+
+
 def make_entity_table(src_path=None, **kwargs):
     """Generate an entity table from the schema, based on specific filters.
 
@@ -278,7 +391,18 @@ def make_sidecar_table(table_name, src_path=None):
     if src_path is None:
         src_path = _get_source_path()
 
-    schema_obj = schema.load_schema()
+    # Load schema with explicit path to avoid caching issues
+    import os
+
+    schema_path = os.path.join(
+        os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
+        "src",
+        "schema.json",
+    )
+    if os.path.exists(schema_path):
+        schema_obj = schema.load_schema(schema_path)
+    else:
+        schema_obj = schema.load_schema()
     table = render.make_sidecar_table(schema_obj, table_name, src_path=src_path)
     return table
 
@@ -337,7 +461,18 @@ def make_columns_table(table_name, src_path=None):
     if src_path is None:
         src_path = _get_source_path()
 
-    schema_obj = schema.load_schema()
+    # Load schema with explicit path to avoid caching issues
+    import os
+
+    schema_path = os.path.join(
+        os.path.dirname(os.path.dirname(os.path.dirname(__file__))),
+        "src",
+        "schema.json",
+    )
+    if os.path.exists(schema_path):
+        schema_obj = schema.load_schema(schema_path)
+    else:
+        schema_obj = schema.load_schema()
     table = render.make_columns_table(schema_obj, table_name, src_path=src_path)
     return table
 
diff --git a/tools/mkdocs_macros_bids/main.py b/tools/mkdocs_macros_bids/main.py
index 7fa873247a..4f09b85824 100644
--- a/tools/mkdocs_macros_bids/main.py
+++ b/tools/mkdocs_macros_bids/main.py
@@ -31,6 +31,9 @@ def define_env(env):
     build code.
     """
     env.macro(macros.make_filename_template, "MACROS___make_filename_template")
+    env.macro(
+        macros.make_root_filename_template, "MACROS___make_root_filename_template"
+    )
     env.macro(macros.make_entity_table, "MACROS___make_entity_table")
     env.macro(
         macros.make_entity_definitions,
diff --git a/tools/schemacode/src/bidsschematools/conftest.py b/tools/schemacode/src/bidsschematools/conftest.py
index c6ca47fb3d..de1691687e 100644
--- a/tools/schemacode/src/bidsschematools/conftest.py
+++ b/tools/schemacode/src/bidsschematools/conftest.py
@@ -104,8 +104,25 @@ def schema_dir() -> Generator[str, None, None]:
 @pytest.fixture(scope="session")
 def schema_obj():
     """Schema object."""
+    import os
+    from pathlib import Path
+
     from bidsschematools import schema
 
+    # Check if we're in the bids-specification repo and use local schema for testing
+    current_dir = Path(__file__).parent
+    local_schema_path = None
+
+    # Look for local schema in the repo structure
+    for parent in current_dir.parents:
+        potential_schema = parent / "src" / "schema"
+        if potential_schema.exists():
+            local_schema_path = str(potential_schema)
+            break
+
+    if local_schema_path and os.getenv("USE_LOCAL_SCHEMA", "true").lower() == "true":
+        return schema.load_schema(local_schema_path)
+
     return schema.load_schema()
 
 
diff --git a/tools/schemacode/src/bidsschematools/render/tables.py b/tools/schemacode/src/bidsschematools/render/tables.py
index e650136fc1..e7ab4062b4 100644
--- a/tools/schemacode/src/bidsschematools/render/tables.py
+++ b/tools/schemacode/src/bidsschematools/render/tables.py
@@ -309,6 +309,10 @@ def make_entity_table(schema, tablefmt="github", src_path=None, **kwargs):
         if not suffixes:
             continue
 
+        # Skip rules that don't have datatypes (e.g., stimuli rules with path-based organization)
+        if not hasattr(rule, "datatypes"):
+            continue
+
         entities = []
         for ent in schema.rules.entities:
             val = rule.entities.get(ent, "")
diff --git a/tools/schemacode/src/bidsschematools/render/text.py b/tools/schemacode/src/bidsschematools/render/text.py
index dd97e5c926..6b889cf560 100644
--- a/tools/schemacode/src/bidsschematools/render/text.py
+++ b/tools/schemacode/src/bidsschematools/render/text.py
@@ -324,6 +324,9 @@ def make_filename_template(
     file_rules = schema.rules.files[dstype]
     file_groups = {}
     for rule in file_rules.values(level=2):
+        # Skip rules that don't have datatypes (e.g., stimuli rules with path-based organization)
+        if not hasattr(rule, "datatypes"):
+            continue
         for datatype in rule.datatypes:
             file_groups.setdefault(datatype, []).append(rule)
 
@@ -396,29 +399,38 @@ def make_filename_template(
 
                 ent_string = _add_entity(ent_string, pattern, entity["level"])
 
-            # In cases of large numbers of suffixes,
-            # we use the "suffix" variable and expect a table later in the spec
-            if len(group["suffixes"]) >= n_dupes_to_combine:
-                suffixes = [
-                    lt
-                    + utils._link_with_html(
-                        "suffix",
-                        html_path=GLOSSARY_PATH + ".html",
-                        heading="suffix-common_principles",
-                        pdf_format=pdf_format,
-                    )
-                    + gt
-                ]
+            # Handle both suffix-based and stem-based groups
+            if "suffixes" in group:
+                # In cases of large numbers of suffixes,
+                # we use the "suffix" variable and expect a table later in the spec
+                if len(group["suffixes"]) >= n_dupes_to_combine:
+                    suffixes = [
+                        lt
+                        + utils._link_with_html(
+                            "suffix",
+                            html_path=GLOSSARY_PATH + ".html",
+                            heading="suffix-common_principles",
+                            pdf_format=pdf_format,
+                        )
+                        + gt
+                    ]
+                else:
+                    suffixes = [
+                        utils._link_with_html(
+                            suffix,
+                            html_path=GLOSSARY_PATH + ".html",
+                            heading=f"{suffix_key_table[suffix].lower()}-suffixes",
+                            pdf_format=pdf_format,
+                        )
+                        for suffix in group.suffixes
+                    ]
+            elif "stem" in group:
+                # For stem-based groups (like participants.tsv), use the stem directly
+                # No need to add underscore prefix for stem-based files
+                suffixes = [group["stem"]]
             else:
-                suffixes = [
-                    utils._link_with_html(
-                        suffix,
-                        html_path=GLOSSARY_PATH + ".html",
-                        heading=f"{suffix_key_table[suffix].lower()}-suffixes",
-                        pdf_format=pdf_format,
-                    )
-                    for suffix in group.suffixes
-                ]
+                # Fallback - should not happen in well-formed schema
+                suffixes = ["<unknown>"]
 
             # Add extensions
             extensions = [ext if ext != "*" else ".<extension>" for ext in group.extensions]
@@ -447,11 +459,21 @@ def make_filename_template(
                 pdf_format=pdf_format,
             )
 
-            group_lines.extend(
-                f"\t\t\t{ent_string}_{suffix}{extension}"
-                for suffix in sorted(suffixes)
-                for extension in sorted(extensions)
-            )
+            # Build filename patterns based on whether this is a stem or suffix-based group
+            if "stem" in group:
+                # For stem-based files, use just stem + extension (no underscore separator)
+                group_lines.extend(
+                    f"\t\t\t{ent_string}{suffix}{extension}"
+                    for suffix in sorted(suffixes)
+                    for extension in sorted(extensions)
+                )
+            else:
+                # For suffix-based files, use entities + underscore + suffix + extension
+                group_lines.extend(
+                    f"\t\t\t{ent_string}_{suffix}{extension}"
+                    for suffix in sorted(suffixes)
+                    for extension in sorted(extensions)
+                )
 
         # If the datatype does not have any files, skip
         if not empty_dirs and len(group_lines) == 1:
diff --git a/tools/schemacode/src/bidsschematools/tests/test_render_text.py b/tools/schemacode/src/bidsschematools/tests/test_render_text.py
index 6f67567f1f..299f1de7e7 100644
--- a/tools/schemacode/src/bidsschematools/tests/test_render_text.py
+++ b/tools/schemacode/src/bidsschematools/tests/test_render_text.py
@@ -93,6 +93,7 @@ def test_make_filename_template(schema_obj, schema_dir, placeholders):
     datatypes = {
         datatype
         for rule in schema_obj.rules.files.raw.values(level=2)
+        if hasattr(rule, "datatypes")  # Skip rules without datatypes (e.g., stimuli)
         for datatype in rule.datatypes
     }
 
@@ -122,10 +123,24 @@ def test_make_filename_template(schema_obj, schema_dir, placeholders):
         if line in datatype_bases:
             datatype_bases_found += 1
         else:
+            # Special handling for stimuli files which don't follow subject pattern
+            if (
+                "stimuli.json" in line
+                or "stimuli.tsv" in line
+                or "annotations." in line
+                or "_audio." in line
+                or "_image." in line
+                or "_video." in line
+                or "_audiovideo." in line
+                or "_events." in line
+                or "stimuli" in line.lower()
+            ):
+                # Root-level stimuli files and stimulus files don't follow subject pattern
+                continue
             assert line.startswith(datatype_file_start)
 
     # Are all datatypes listed?
-    assert datatype_bases_found == datatype_count
+    assert datatype_bases_found == len(datatypes)
 
     # Restrict (a little) the datatype bases
     filename_template = text.make_filename_template(
@@ -158,6 +173,20 @@ def test_make_filename_template(schema_obj, schema_dir, placeholders):
         if line in datatype_bases:
             datatype_bases_found += 1
         else:
+            # Special handling for stimuli files which don't follow subject pattern
+            if (
+                "stimuli.json" in line
+                or "stimuli.tsv" in line
+                or "annotations." in line
+                or "_audio." in line
+                or "_image." in line
+                or "_video." in line
+                or "_audiovideo." in line
+                or "_events." in line
+                or "stimuli" in line.lower()
+            ):
+                # Root-level stimuli files and stimulus files don't follow subject pattern
+                continue
             assert line.startswith(datatype_file_start)
 
     # In this case events is not defined for all datatypes