JTAG (jay-tag) is one of the engineering acronyms that have been transformed into a noun, although arguably it is not so popular as RAM, or CPU. IEEE Std 1149.1-1990 IEEE Standard Test Access Port and Boundary-Scan Architecture is the official name, but JTAG is a bit snappier and is an abbreviation of Joint Test Action Group. To help a user migrate to IA32, this white paper gives a quick overview of the various implementations, and names, of JTAG debug methods for users familiar with other processors.