id,summary,reporter,owner,description,type,status,priority,milestone,component,version,severity,resolution,keywords,cc
23430,sanitize_user() disallows + in usernames causes problem for email as username,jb510,,"I want to use email addresses as usernames which seems to work fine, except sanitize_user() doesn't allow a + in the username and my email addresses have + in them.  

Google/gmail allows one to use a + modifier on emails like so:
user+admin@gmail.com, user+editor@gmail.com, user+author@gmail.com, etc...

I often use this to get around WordPress's requirement for unique email addresses but it's also intended for and useful in filtering: user+blog1@gmail.com, user+blog2@gmail.com, etc...

Is there a reason we can't allow +'s in usernames or could it be moved to the strict case only?  

See formatting.php:892

",enhancement,new,normal,Awaiting Review,Users,3.5.1,minor,,has-patch,jbrown510@…