... (?: , | \b)). ? allows the preceeding character to be optional (but there is no preceeding character?) and I can't see the use of a colon in this context.

The  (?:pattern) construct defines a non-capturing group. See Extended Patterns in perlre. This and other statements in your reply lead me to suggest that you take a big step backwards and read up on basic regex docs. Please see perlre. In particular, see perlretut for a very good tutorial. (I'm not familiar with the material in the Cozens book.) See also perlrequick for a quick reference. See also the material in the "Pattern Matching, Regular Expressions, and Parsing" area of the Tutorials section of this site.

In reply to Re^3: RegExp substitution by AnomalousMonk
in thread RegExp substitution by Keystone

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