template_preprocess_comment in modules/comment/comment.module
Process variables for comment.tpl.php.
template_preprocess_node in modules/node/node.module
Processes variables for node.tpl.php
template_preprocess_profile_block in modules/profile/profile.module
Process variables for profile-block.tpl.php.
template_preprocess_profile_listing in modules/profile/profile.module
Process variables for profile-listing.tpl.php.
user_account_form in modules/user/user.module
Helper function to add default user account fields to user registration and edit form.
user_user_view in modules/user/user.module
Implements hook_user_view().