Specification items
Forgive me if I use "spec" and "specs" from now on. "Spec(s)" will refer to the sheet itself, or, more accurately, to its contents, and "specification(s)" will be used in the context of a sentence; thus, I hope, confusion will be avoided. Here, the items on the spec sheet are listed and a brief description is given of each.
Page size
Not really the responsibility of the proofreader, the page size is the physical length and width of each page after trimming. As you know, all books differ in these respects, so this is a printing/typesetting spec. Proofs are always much bigger than the trimmed size, but the guides show where the trim
