Minor fix for clarity after PR25072

Author: Bob

contributing_to_docs/doc_guidelines.adoc

@@ -130,7 +130,7 @@ link:https://redhat-documentation.github.io/modular-docs/#forming-assemblies[Red
 
 [NOTE]
 ====
-For `Prerequisites`, `Next steps`, and `Additional resources` headings, use `==` formatting in assembly files. Do not use `.Prerequisites`, `.Next steps`, or `.Additional information`, as this syntax should only be used within module files to suppress TOC formatting.
+When using `Prerequisites`, `Next steps`, and `Additional resources` headings in an assembly, use `==` formatting, such as `== Prerequisites` and `== Additional resources`. Use of this heading syntax at the assembly level indicates that the sections relate to the whole assembly. Only use `.` syntax (`.Additional resources`) to follow the module as a trailing include at the assembly level, which indicates that the resources apply specifically to the module.
 ====
 
 == Writing concepts
@@ -155,7 +155,7 @@ link:https://redhat-documentation.github.io/modular-docs/#creating-procedure-mod
 
 [NOTE]
 ====
-When needed, use `.Prerequisites`, `.Next steps`, or `.Additional information` syntax to suppress TOC formatting within a module. Do not use `==` headings or xrefs in modules.
+When needed, use `.Prerequisites`, `.Next steps`, or `.Additional resources` syntax to suppress TOC formatting within a module. Do not use `==` headings or xrefs in modules.
 ====
 
 == Product name & version