in reply to exist backreference variable list?

Hi, Mark, I frankly don't understand what you're asking. Can you please elaborate?
Earlier in the chapter it notes that when using a Regular Expression with grouping, the sucker "eats up" hits and stores them in incrementally changing variables of $1, $2...
It seems to me the book didn't make the way capture groups (parens) work in Perl's regexes clear? Perhaps it's just not a good book?