I think I get what Elk is looking for - and that is whether manufacturers mislead customers and officials by testing products themselves and NOT listing them.
That is probably too deep of a subject for us to explore, because it would be difficult to prove, and certain instances of it must even be allowed. In other words, certain basic materials may be so common as to be allowed to be "tested" without being "listed and labeled".
And, even though it is always nice to get to the bottom of things, it is probably not in the realm of an inspector or sweep/installer to usually follow the whole thing back to "ultimate" proof....that would mean one would have to do so with ALL building materials, appliances, electronics, etc.
An example of this might be with chimney caps - NFPA might say that chimney caps or hoods, or dampers for that matter - have to be made of steel that is 20 ga or thicker, or of stainless steel. They may specify the screen size in a chimney cap. So a manufacturer would be (probably) fully within their rights to claim "meets NFPA guidelines" or other similar statements....even "exceeds NFPA".
Testing is often done on a "system". In these cases, the actual mark of the testing lab is usually on the product or at minimum on the manual or literature. I think that is one "rough" way of knowing if a "system" is listed.
Actually Elk, you are probably correct that there is a lot of misinformation out there - but what is exactly "right" is another story. As we see by the NFPA paragraph I posted above, placing some patching cement in a cracked tile may meet the intention of the standard. So I think this is a matter of:
Adequate
Decent
Good
Better
Best
Rolls Royce
in many cases. In other words, there is little doubt that those .000000005 (my joke) liners will not last as long or hold up as well as a listed Heat-Fab or Dura or Ventinox system. But the $300 price tag attracts many buyers. They may have to replace it in 10 years when the chimney brush goes right through it.
There is no doubt that the best system is the best system - and it's actually probably the poured-in-place liners done right! But one thing I learned in the retail world is that you have to have a "seat for every arse" - and while we never sold unlisted products, we did sell some that were cheaper.
I think that ALL the lining manufacturers can provide you with some kind of test report from an agency - and probably a listing also. However, in the real world it is doubtful that every screw, cap, insulation, fitting, etc. will match up with that listing report.....and that is where discretion comes in. A stainless pop-rivet is as good (well, actually better in many cases) than a screw.
As a retailer and installer, the question I would always ask myself is whether I am making it (the situation) safer. Maybe I have low standards, but I didn't ask "am I making it as safe as it can possibly be, with no expense spared", because no matter what we like to think $$$ figures into everyones calculations.
if we asked that question, none of us would drive in anything else but the safest car on the road.....as it is, we often buy the safest we can afford - which is all in all, MUCH safer than what we had before.