Names and References for Pali Thai Script Orthographies

There are two ways of writing Pali in Thai. The first one, the official way, uses implicit vowels and phinthu and uses nikkhahit for anusvara, and never uses mai han akat or sara a. The second way, which follows the spelling rules of Thai, uses mai han akat and sara a and uses ngo ngu for anusvara. Are there names for these two methods, and is there an authoritative reference for their existence? I feel I should document them on Wikipedia, but I can't use 'original research'. For example, Pali gacchāmi 'I go' is written respectively คจฺฉามิ and คัจฉามิ.