Retired in ISO 639-3: merged with Mandaya [mry]
Excerpt from change request document:
The present codes for Mandaya (mrt, mry, and mst) do not represent dialects of Mandaya but data collection points when Andrew Gallman was gathering data for his dissertation some 30 years ago. In reality it is all the same language with a purer Mandaya in the mountains and more of a mixed variety of Mandaya along the coast. All of it is Mandaya.