Thanks Naga and looking at the link shows that others were, and maybe still are, using this mix as well. It contains the most common always there spices plus Amchoor / Amchur (mango powder).
The variety of others spices used in some mixes is quite significant. It seems you can put whatever you like in it and still call it by a "standard" name. As a person who has studied chemistry, where the presence of an extra atom creates a differently named molecule, this is disturbing. ;D