The IEEE priority standard originally was published as 802.1p. It later was incorporated into the joint VLAN and priority standard:
IEEE 802.1Q. "Virtual Bridged Local Area Networks." 1998.
The GARP VLAN Registration Protocol also is described in 802.1Q.
The Generic Attribute Registration Protocol (GARP) is described in Chapter 12 of the standard:
IEEE 802.1D. "Media Access Control (MAC) Bridges." 1998.
VLAN implementations vary greatly from vendor to vendor. The best way to get a sense of the capabilities that are available is to check the configuration manuals for products from vendors such as Cisco, 3Com, Nortel, and Cabletron.