When are keywords substituted?

[Nick Patavalis]

Reading from the CVS (info) manual [keyword substitution / using
keywords]:

  To include a keyword string you simply include the relevant text
  string, such as `$Id$', inside the file, and commit the file.  CVS
  will automatically expand the string *as part of the commit
  operation*.

Is this true? I thought that expansion occured as a part of the
*export* (cvs checkout, cvs diff, cvs export, etc) operations.

/npat

-- 
Beware of bugs in the above code; I have only proved it correct, not
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  -- Donald E. Knuth