diff --git a/docs/endpointprotector/admin/denylistsallowlists/denylists.md b/docs/endpointprotector/admin/denylistsallowlists/denylists.md
index cea6e6e05c..c6505b272d 100644
--- a/docs/endpointprotector/admin/denylistsallowlists/denylists.md
+++ b/docs/endpointprotector/admin/denylistsallowlists/denylists.md
@@ -164,9 +164,9 @@ You can test a regular expression for accuracy using the right-side option. Add
click Test. If the Regular Expression has no errors, then the same content should appear into the
Matched content box, as shown below:
-- To match an E-mail – [-0-9a-zA-Z.+_]+@[-0-9a-zA-Z.+_]+\.[a-zA-Z]{2,4}
+- To match an E-mail – `[-0-9a-zA-Z.+_]+@[-0-9a-zA-Z.+_]+\.[a-zA-Z]{2,4}`
- To match an IP –
- (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}
+ `(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)(\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)){3}`
:::note
This feature is provided “as is” and requires advanced knowledge of the Regular Expression
@@ -177,6 +177,66 @@ implement regular expressions and to thoroughly test.

+### Regex Supported Formats
+
+Endpoint Protector supports both standard Regex syntax and **Perl-Compatible Regular Expression (PCRE)** extensions and modifiers. For example, you can use the (?i) modifier at the beginning of a regex pattern to make it case-insensitive during matching.
+
+**Case Sensitivity Options in Regular Expressions**
+
+Regular expressions allow you to control how text matching handles letter casing. Depending on your requirements, you can use case-sensitive, case-insensitive, or partially case-insensitive matching.
+
+**1. Case-Sensitive Matching (Default)**
+
+By default, Regex matching is case-sensitive.
+This means that only text with the exact same casing will be matched.
+
+**Example:**
+**Pattern:** `test@example\\.com`
+**Matches:** `test@example.com`
+Does **not match:** `TEST@EXAMPLE.COM` or `Test@Example.Com`
+
+
+**2. Case-Insensitive Matching**
+To make a Regex pattern case-insensitive, use the (?i) flag.
+This enables matching regardless of the case of letters in the input text.
+
+**Example:**
+**Pattern:** `(?i)test@example\\.com`
+**Matches:** `test@example.com`, `TEST@EXAMPLE.COM`, `Test@Example.Com`
+
+**3. Partial Case-Insensitive Matching**
+Regex also allows you to apply case-insensitive matching only to specific parts of your pattern.
+ You can enable and disable this mode using the following flags:
+
+- `(?i)` — enables case-insensitive mode
+- `(?-i)` — disables case-insensitive mode
+
+**Example:**
+**Pattern:** `(?i)confidential(?-i) document`
+**Matches:** `"CONFIDENTIAL document"`, `"Confidential document"`
+Does **not match:** `"CONFIDENTIAL DOCUMENT"`
+
+**Regex Operators**
+
+| **Character** | **Description** | **Example** |
+|---------------|-------------------------------------------------------------------------|----------------------------------------------------------------------|
+| ˆ | Matches the start of a string or line. | \^abc matches “abc” only if it appears at the beginning of the line. |
+| \$ | Matches the end of a string or line. | abc\$ matches “abc” only if it’s at the end of the line. |
+| . | Matches any single character except newline (\\n). | a.c matches “abc”, “axc”, etc. |
+| \* | Matches 0 or more occurrences of the preceding character or group. | bo\* matches “b”, “bo”, “boo”, “booo”, etc. |
+| [] | Defines a character class, matching any one of the enclosed characters. | [abc] matches “a”, “b”, or “c”. |
+| [abc] | Any single character of a, b or c | [abc] matches “a”, “b”, or “c”. |
+| [ˆabc] | Any single character expect a, b or c | It will match any single charact expect “a”, “b”, or “c”. |
+| [a-z] | A character in range a-z | It will match single character in range of a – z. |
+| [a-zA-Z] | A character in range a-z & A-Z | It will match single character in range of a – z & A - Z |
+| \\d | Any digit character | \\d will match any digit 0-9 |
+| \| | Groups expressions together or captures them for backreferences. | (abc)+ matches one or more repetitions of “abc”. |
+| () | Groups expressions together or captures them for backreferences. | (abc)+ matches one or more repetitions of “abc”. |
+| \\ | Used to escape special characters or indicate special sequences. | \\. matches a literal period “.”; \\d matches any digit. |
+| (?i) | Enables case-insensitive matching. | (?i)abc matches “abc”, “ABC”, “AbC”, etc. |
+| \\s | Any whitespace character | |
+| \\S | Any non-whitespace character | |
+
## Domain and URL
Domain and URL Denylists are custom-defined lists of web addresses identified by Endpoint Protector.