oops, I missed the one with a colon :( 
(?: # begin non capturing group
CR|ID # alternation accepts either pattern group 'CR' or 'ID'
)? # group is optional

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print "Good ",qw(night morning afternoon evening)[(localtime)[2]/6]," fellow monks."

In reply to Re^2: Problem with regular expression by Utilitarian
in thread Problem with regular expression by MARVion

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