ABOUT CALLNO

My format exit, called CALLNO, provides support for
call numbers such as used at the National Library of
Medecine, but with some minor changes, could be adapted
for similar styles of call numbers (e.g. Library of
Congress Classification numbers). The approach taken
was to expand the call number, inserting blanks as
required to align the different subparts of the number.

To install the program, start by copying the 
program to your PROGRAM subdirectory (normally
called prog). The file should be called CALLNO.PAS.
Compile the program by running CDS/ISIS, choosing A
for Advanced Programming Services from the Main Menu,
then C for Compile, and entering CALLNO as the
program name. Return to the main menu.

To call the format exit, in your sort worksheet where you
enter the sort key, enter 20 for the length of the sort key.
Where you would normally enter the FST for the sort key, use
the following format:
                  &callno(xxx)/
where xxx represents a format that will produce your call
number. For example, if your call number is found in
subfield a of field 610, your FST should look something
like:
             99 0 &callno(v610^a)/
where 99 is the tag of the generated heading and 0 is the
heading processing indicator.

The sort key generated by the format exit doesn't look
very pretty for printing as a heading: you should use
the data as entered in the field for printing purposes.
Or you can copy and edit this program to extract only
the main class or main class and subclass and use that as
a heading. In any case, as full call numbers are unique,
headings are less useful here than in other kinds of lists.
--
Ron Davies                           rdavies@bibliom.synapse.net
Bibliomatics Inc.                    Tel:    (613) 523-7981
48-200 Owl Drive, Ottawa, Canada     Fax:    (613) 523-4417