_C.ISM, _P.ISM and WSP files

SOLVED

A customer reported that after they deleted the _P and .WSP files for a user, that user no longer had his customizations and couldn't print to PrintBoss.

I don't understand why that would be true since PrintBoss is just a printer. I figured it would be added when the user went into Sage for the first time after _P was deleted. 

_C stores customizations like new report icons, right?

_P stores printers 

I don't have a clue what .WSP stores. 

Any thoughts (besides restore from backup and rename instead of delete next time)?