feel free to keep it strictly simple...
statusflags

We added new entries to statusflags in /framework/sys.constants.php

 

define( 'USERS_PROFILE_ALLOWED', 16 ); // user can create a profile page
define( 'USERS_PROFILE_AVAIL', 32 ); // user has fullfilled profile and can not be deleted via core

 

This enable addons authors to use the statusflags 32 to prevent the system core from deleting users with statusflags 32 from users table.

This might be neccessary, if an addon depends on users table data and inserts directly in the user table.

 

Please keep in mind to change stausflags to != 32 during module's uninstalling process so the core is able to delete those entires.

Or think about deleting users with statusflags 32 directly from users table during uninstall procedure.