address review comments

Author: Shikha Maheshwari

README.md

@@ -21,10 +21,9 @@ You can see the published documentation at https://terraform-ibm-modules.github.
 - Maintaining the GitHub project
     - [Maintainers contribution process](https://terraform-ibm-modules.github.io/documentation/#/maintain-module.md)
     - [About merging pull requests](https://terraform-ibm-modules.github.io/documentation/#/merging.md)
-- Deployable Architecture Reference Docs
-    - [Prefix Usage Guide](https://terraform-ibm-modules.github.io/documentation/#/DA-prefix.md)
 - Reference
     - [Module authoring guidelines](https://terraform-ibm-modules.github.io/documentation/#/implementation-guidelines.md)
+    - [Deployable Architecture authoring guidelines](https://terraform-ibm-modules.github.io/documentation/#/da-implementation-guidelines.md)
     - [Design guidelines](https://terraform-ibm-modules.github.io/documentation/#/design-guidelines.md)
     - [Module structure](https://terraform-ibm-modules.github.io/documentation/#/module-structure.md)
     - [Metadata file (index.yml)](https://terraform-ibm-modules.github.io/documentation/#/module-catalog-metadata.md)

docs/_sidebar.md

@@ -13,6 +13,7 @@
     - [About merging pull requests](merging.md)
 - Reference
     - [Module authoring guidelines](implementation-guidelines.md)
+    - [Deployable Architecture authoring guidelines](da-implementation-guidelines.md)
     - [Design guidelines](design-guidelines.md)
     - [Module structure](module-structure.md)
     - [Metadata file (index.yml)](module-catalog-metadata.md)

docs/DA-prefix.md renamed to docs/da-implementation-guidelines.md

@@ -1,4 +1,6 @@
-# Prefix in Deployable Architecture
+# Deployable Architecture authoring guidelines
+
+## Prefix in Deployable Architecture
 
 The **`prefix`** input variable allows you to prepend a custom string to the names of all resources created by this automation. This is especially useful for:
 
@@ -40,7 +42,17 @@ To ensure compatibility and consistency, the prefix must follow these rules:
 Here is the code snippet for your reference.
 
 ```hcl
-validation {
+variable "prefix" {
+  type        = string
+  nullable    = true
+  description = "The prefix to be added to all resources created by this solution. To skip using a prefix, set this value to null or an empty string. The prefix must begin with a lowercase letter and may contain only lowercase letters, digits, and hyphens '-'. It should not exceed 16 characters, must not end with a hyphen('-'), and can not contain consecutive hyphens ('--'). Example: prod-0205-cos."
+
+  validation {
+  # - null and empty string is allowed
+  # - Must not contain consecutive hyphens (--): length(regexall("--", var.prefix)) == 0
+  # - Starts with a lowercase letter: [a-z]
+  # - Contains only lowercase letters (a–z), digits (0–9), and hyphens (-) 
+  # - Must not end with a hyphen (-): [a-z0-9]
   condition = (var.prefix == null || var.prefix == "" ? true :
     alltrue([
       can(regex("^[a-z][-a-z0-9]*[a-z0-9]$", var.prefix)),
@@ -49,10 +61,10 @@ validation {
   )
   error_message = "Prefix must begin with a lowercase letter and may contain only lowercase letters, digits, and hyphens '-'. It must not end with a hyphen('-'), and cannot contain consecutive hyphens ('--')."
  }
-
   validation {
    # must not exceed 16 characters in length
     condition = length(var.prefix) <= 16
     error_message = "Prefix must not exceed 16 characters."
- }
+  }
+}
 ```