bug#74065: documentation suggestion for caret

[Greg Minshall]

in the info node
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5.3 Overview of basic regular expression syntax
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in the discussion of caret (^), there is this (totally correct, afaik)
text:
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     ‘^’ acts as a special character only at the beginning of the
     regular expression or subexpression (that is, after ‘\(’ or ‘\|’).
     Portable scripts should avoid ‘^’ at the beginning of a
     subexpression, though, as POSIX allows implementations that treat
     ‘^’ as an ordinary character in that context.
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on the other hand, POSIX *EREs* allow caret in a subexpression.  this
isn't mentioned in the info node about EREs (which, as that node treats
GNU sed EREs, probably needn't be).  would it be worth mentioning it
here?
----
     ‘^’ acts as a special character only at the beginning of the
     regular expression or subexpression (that is, after ‘\(’ or ‘\|’).
     Portable scripts should avoid ‘^’ at the beginning of a
     subexpression, though, as POSIX allows implementations that treat
     ‘^’ as an ordinary character in that context.  (Note that POSIX
     *extended* regular expressions, as well as those of GNU sed, do
     allow '^' at the beginning of a subexpression.)
----

cheers.