Other identifiers like print and oct that have ordinary function or operator syntax will be called built-ins, if anything. Localizing a variable means creating a separate scope for it that applies through the end of the enclosing block or file. Special variables must be localized with the local operator. It should be mostly self-explanatory, but here is a brief overview. That's all there is to the basics.
Style is, of course, a matter of preference and debate.
The fact that the code appears in a book affects its style somewhat. It's just too verbose for this little book. Furthermore, English is not common practice among Perl programmers, and scripts that use English suffer a speed penalty. This is not to say that English is not useful, just that you won't see it here. I advise all Perl programmers to make use of both -w and use strict regularly.