Discussions about standards aside, it seems like one should be able to determine whether a combination of parts in hand will work without excessive danger.
A somewhat snug fit of the tire bead is desired here, if you are able to push a deflated but still mounted tire bead off the bead seat and into the well without any resistance, it's probably not tight enough for tubeless, right? So you could install the recommended amount of rim tape (usually two layers) to the bare rim, install the tire with a regular tube, and inflate/deflate. Test pushing the tire bead away from the edge of the rim, and if it's too loosey-goosey, add another layer of rim tape
as recommended by Jan/Compass. Once you're satisfied with the fit of the bead you can try setting it up tubeless. Put in the eye protection and earplugs, and take the pressure up to the manufacturer's recommended max. Assuming that works, go a little beyond, looking for evidence that the tire is creeping. Sort of like finding out how far you can push a set of old straight-sided rims, really.
This is all with the caveat that I haven't actually played around with tubeless, myself. Not against it, just haven't gotten around to it yet.