This is a proposal to limit numbers in library names to the range 0 to 32767. Currently, there is no portable lower bound which all Schemes can assume as the maximum size of an integer, unless ticket #349 passes, in which case the limit will be 224 - 1, or 16777215.
Numbers are mostly used for SRFI-based libraries anyway, which are not likely to reach either limit.
WG1 decided not to impose any limit.