@Ya Block It's either:

1: An old sheet where the ripper isn't credited and they don't know who ripped it. It's mainly sheets imported from The Shyguy Kingdom or a few early Sounds Resource submissions.
2: From a banned member. Sometimes there are a few clues on who ripped the sheets though like you could guess who ripped a few Looney Tunes sheets or cross reference from other sites where the ripper isn't banned. I think this sheet comes from the latter...

In the past you could look into the profile for all the sheets not credited to a ripper but doesn't seem to be that way now.

@Doc Not always...

@Ya Block Those are just anonymous submissions from before it became basically required to tag your work on the submit page.

Who is ? and why is their submitions page forbidden