[wp-hackers] what's the purpose of user_status field in wp_users table?

[dave jaggy]

I need to store user status somewhere. I don't want it to reside in
meta table, 'cause it brings some joining and compatibility issues to
my code.

I wonder what's the purpose of user_status field in wp_users table? Is
it used somewhere? As far as I see it is zero for admins and
subscribers. Can I break something if I put my user status into it?