The notes on 583 states - 

Julius Schwartz autograph; Continued from Superman #423; Last pre-Crisis on Infinite Earths Superman

 

I have two copies of 583 and they do not have any signatures. I created Variation A because noting that they are not signed. Tried to Submit New or Corrected Data but program states cannot connect to ComicBase server.

So trying this route to get the info to ComicBase.

Generally, if a signed issued does not have a COA (Certificate of Authenticity), CB does not track them.

Since this does not appear to have a COA, then there is no need for a variation.

PS However, if you or anyone else has a signed copy, you can, of course, add it to your database. Just don't submit it as New or Corrected data.

 

I put signatures in the Grading Notes if they're not a limited edition.