Go to http://www.videohelp.com/dvdmedia and do a search for "TYG02" and "TY02"; observe the difference in the number of results returned.
This site has plenty of lists of media codes supported by various firmwares. Find me one that has TY02 in it.
Find one instance of TY02 anywhere on cdfreaks.com that occurs in a screenshot or in an automated media code block dump and is not human-typed.
Until then, I stand by my assessment that T02 and TY02 are nothing more than bad, confusing abbreviations of YUDEN000T02 and TYG02.