Looks for phone numbers in your .bbdb with a particular area code
and one of a set of exchanges and changes the area code. The old
and new area codes are specified on the command line, as is the
location of a file that contains the exchanges that are being
changed. (The format of that file is very loose. Every three digit
sequence will be used.)
This manual page was written for the Debian distribution
because the original program does not have a manual page.
Instead, it has documentation in the GNU Info format; see below.