The worded selvedge isnt randomly used, it is always on specific designs, more recently the one colour Mad patch RMCs and Tiger RMCs but it also appears on the Pirate part paint/part embroidered RMC, and the Heineken Red Star RMCs too. Think the Tropsicle RMC design has it too and the Yakult RMC and Mad patch to name just a few. There are probably more but off the top of my head I cant think of them. Bear in mind there are 2 worded selvedges, a RMC Martin Ksohoh one and a seperate Yoropiko one ( which oddly I dont think has actually ever been used on a Yoropiko other than a prototype Starwars, I'll have to double check LOL), both really add to the exclusivity of the denim in my opinion.
This is the one used on the majority of designs which have worded selvedge:
And this is the rarer type found on the RMC mad patch: