IMSLP Forums

Hi all,
From time to time I come across "ICS" catalogue numbers. (Today I'm looking at Carl Stamitz Duos.)
What means "ICS"? What institution gives these numbers?
(I couldn't find anything about that on the IMSLP:FAQ page.)

Thanks!
Pierre.

I stands for IMSLP, C vor Carl, S for Stamitz. The numbers are assigned automatically, e.g. to distinguish between pieces with the same title.