Unlike most of the 'fads' Puzzling SE has seen (the Security to the Party puzzles of late 2014, the rebus craze of early 2015, the $n$ Words (----||||) puzzles of mid-2015, and so on), these puzzles have withstood both the twin tests of time and votes. Usually such 'fads' don't last long - a few months at most - and the question scores rapidly decline after the first one or two posted as people get bored of the idea. But the ™ puzzles have lasted for over a year and are still popular today, with at least one of them on the HNQs at the time of this writing. It looks like they're good quality and here to stay.
Moreover, there really is a specific type of puzzle here: the ™ thing isn't just a gimmick that could be put on many more puzzles than it is. They're a 'sequence' defined not just by a common flavour text and OP like the Ernie or Mysterious Email puzzles, but by the following definitive puzzle type:
- some unknown property of certain words/phrases is to be found
- a list of words with this property is provided, and also some without it for comparison.
I propose that we create a tag for this type of puzzle.
For want of a better tag name, how about tm-puzzle?
(Yes, I realise that this would be a sub-tag of pattern, but we've already established that sub-tags and super-tags are OK here. Popular tags such as mathematics and logical-deduction already have various sub-tags covered by them.)