Contact/Subscription collections

I’m trying to tidy up my project and I’m reviewing all the collections I use.
I notice I have the following collections that I did not define:
Contact 2
contact4
feedback01
lightboxContact02
;ightboxSubscribe03
lightboxSubscribe32

These are all empty except for contact4 which is obviously a log of contacts made to the web site.

Can anyone tell me which app these belong to, and can they be removed without affecting the web site operation. I do use the Forum app.