Excerpt from change request document:

In short, the rationale for this proposed change is that no proper evidence has ever been presented for Pongyong's [pgy] existence as a unique language. As far as Nepali linguists can tell, this is a "ghost entry" in the ISO 639-3. “Pongyong” is a Rai clan name (Van Driem 2001:623). It is unlikely to be a separate language from Saam [raq]. The existence of Pongyong as a unique language was originally based on a single questionnaire by the German survey published by Hansson (1988:20-21; 1991:76-77, 84-85), which is known for having sometimes made big claims based on almost no data (such as is the case with Pongyong). Due to such scanty data, Hansson himself hedged to say that Pongyong may be a part of Saam [raq] (Hansson 1988:20-21; Hansson 1991:61, 85). I have not yet found any Kirati language scholars that have heard of Pongyong suggested as a unique language (outside of Hansson's work) or of Pongyong claimed by anyone as their own language. There is also little documentation (albeit some) about Saam, so there does not seem to be enough evidence to merge these ISO code elements. It seems that the Pongyong code element should be eliminated from ISO 639-3 or at grouped together as a part of Saam [raq] if for some reason that is necessary. I think eliminating the [pgy] code element makes the most sense.