This is another of O'Reilly's small format books that really will fit in a pocket. I do wish O'Reilly would work out how to make books in this format lie flat, because as they are you have to hold them open with one hand while typing with the other.
If you need something to remind you of Perl syntax/semantics while away from your normal work area, this will do nicely. The first paragraph on page 1 says all you need to know when it comes to deciding if this is the version for you:
The Perl Pocket Reference is a quick reference guide to Larry Wall's Perl programming language. It contains a concise description of all statements, functions, and variables, and lots of other useful information. This edition is based on Perl version 5.8.