Token Drupal module description
Tokens are small pieces of text that can be placed into larger documents through simple placeholders like %site-name or [user]. The Token module provides a centralized API for modules that use these tokens, and it also allows you to define your own token values.
Note that the Token module itself does not provide any user-facing features. It only offers token handling services to other modules.
For Drupal 6, the Token module includes a Token Actions submodule, which can be enabled separately. This provides additional actions for Drupal’s core Actions/Trigger modules, which benefit from token-based replacement functionality.
Modules that use the Token module and provide tokens through its API include Organic Groups, Pathauto, Comment Notify, and Commerce. You can also browse a full list of modules that use or provide tokens by checking the issue queue tagged with "token".