7 calls to user_module_invoke() in Drupal 4

user_edit_submit in modules/user.module

user_edit_validate in modules/user.module

user_load in modules/user.module

Fetch a user object.

user_login_submit in modules/user.module

user_pass_reset in modules/user.module

Menu callback; process one time login link and redirects to the user page on success.

user_register_validate in modules/user.module

user_save in modules/user.module

Save changes to a user account or add a new user.