IEEE Standard 1076, VHDL Language Reference Manual, is maintained by the P1076 Working Group, also known as the VHDL Analysis and Standardization Group (VASG). The ISAC is the subcommittee of VASG responsible for answering questions of interpretation of the standard and for screening reported issues. Such issues include reports of errors and ambiguities in the standard, as well as requests for enhancement.
If you are an expert in VHDL and would like to become involved in ISAC, your participation would be welcome. You can contact the ISAC Chair, Chuck Swart, by email (cswart at model dot com) for more information.