™ is a warning, advertising that you are claiming the name/logo as a trademark... but it's not required. Any name/logo that's used to trade a product is automatically a trademark, and you can choose to sue others for trademark infringement if they use similar names/logos.
Same with © -- it's just a warning, not a requirement.
That's right, but I yet have to encounter a registered trademark or trademark-by-use or a copyrighted work which doesn't one of those prominently displayed. Heck, most people and businesses even write stuff like
"This software works for Microsoft (TM) Windows(TM)" despite not being related to either one or the owning company in any way.
Hence I think that saying you're "99.9% good" is a fair bet. Of course it's not 100% certain (and image search, while having improved a lot, is still far from perfect, so I gave it rather 80% than 99% because you might actually not find an image mark although it's on the web).
When I worked at a big corporate multi-national, we had a change of policy where we decided to remove all ™ symbols from our products and marketing materials. The idea behind this policy is that it gave us greater scope to sue other people -- we could decide later on whether we thought something was a trademark or not, whereas in the old policy of ™-tagging, we had to decide up-front.
That's some malice. I'm surprised to hear that anyone but a patent troll would attempt such measures at all. Did this actually work (other than for blackmailing indie competitors)? Did you ever successfully go to court with such a thing?
I would be surprised if that worked. Normally there would have to be some kind of "product identity" relating to a word, which you would have to demonstrate. You cannot just sue someone for saying "book" or "table" or "big book".
(Then again the Tolkien consortium sued TSR over "hobbit" which is an English word that demonstrably existed over a hundred years before Tolkien was born... but I guess they could only because TSR's hobbits were a 100% rip-off based on the characters in the books, by their appearance, abilities, etc)
Sure enough, if someone makes a cell phone and calls it iPhone, then that's a trademark whether they write (TM) or not. But that's a hugely different (and obvious) thing.
I was more thinking along the lines if you make, say, a virus scanner, and you want to market a super secret new scan method which is just as bad as any other ("deep scan", "bulletproof detection" or "cloud scan" or "nuclear scan"). I am pretty sure that nobody would try to, or even could sue you (well... successfully, you can sue anyone for anything in the US) for using "deep scan", unless they market that exact combination of words as product identity. And for that, it needs to be prominently visible in some way. Just having said a word once or twice in your life doesn't grant you any rights (that would mean you have a trade mark on the entire language).
If you enter "deep scan" into Google... (let's see)... surprise. Turns out that's a mark owned by Sega for an old Atari game. I really half-expected to find Symantec's or Kaspersky's site in the search results...
