I'll just add that's version 1.4 (Acrobat 5) which is typically what many digital printing companies will request if possible. After 1.4 it was basically all us

I'll just add that's version 1.4 (Acrobat 5) which is typically what many digital printing companies will request if possible. After 1.4 it was basically all useless features being added which bloat the file size (though 1.4 has a bunch too). So later versions of the spec will be longer. I do like the spec a lot and have actually used it to track down bugs in files before. It's very easy to follow if you're just looking at certain operations.