Third letter: an alphabetical counter of the artists with the same first two-letter code, not indicative of musical style.  Since it would be too difficult to insert something alphabetically, the system counted by letter.  So, taking an example from Mark's playlist:  Eddie Hodges, HEA, was the first "HE" to be filed.  If, for example, Edwin Hawkins had been the second, he'd be HEB.  [Editor's Note:  You mean you don't remember, Paul?!]   If Ersel Hickey was the third, he'd be HEC.  The numbers, of course, refer to the specific record as filed, not necesssarily in order of release.  (But fairly often.)

More than three letters:  after using A through Z to count to 26, it was back to A again.  The "SS"'s had a large number of artists, so the second round, after SSZ, would be SSAA, then SSBB, etc.  Back to SSAAA (or SS3A), SS3B, etc.  Interesting that Sam The Sham got to SSWWWW!

I was greatly edified when people realized that the system did indeed function, as long as everyone refiled their stuff.  I remember an early 60s 'Broker, M. L. (I don't remember her full name, but I bet Jack, Mike, P. T. or Charlie Brown would) exclaiming "Omigod, it works!" one day as she was pulling her show in the record library as I was doing some filing.  (With a computer now, instead of the card file, I think the system would still hold up quite well.)  FYI, I think the whole thing took most of three semesters to complete, which would explain my high position on the Dean's List for Academic Atrocity.

- Paul, January 2005