Q:

Is Meta.SE the right forum to ask about specific wording's fit with "be nice" policy?

We have general guidelines to the "Be Nice" policy, but they seem more along the lines of Supreme Court's famous "I know it when I see it" - which leads to supreme unhelpfulness to someone who is trying to answer a binary issue of "do I flag this specific wording, or am I being too sensitive about things".
The question is: in that situation, would asking on Meta.SE (including specific wording, but – presumably – excluding links to specific posts) be considered an appropriate venue to help guide the would-be flagger in the process of decision?
Please note that I anticipate at least one of the answers to be "When in doubt, always flag". That answer doesn't seem to address the root problem I have, which is a lack of non-personally-subjective resource to rely on when making flagging decisions.
This question arose from the perspective of the would-be flagger, but obviously, the same resource question might also be helpful to someone handling the flags

A:

Oh, it's absolutely like the Roth test. There can be no objective standards here; what matters is what actually offends people, not what folks say should offend. 
The guidance - now and forever in the past - is to flag when you see something rude or offensive. If others disagree with you, so be it. The guidance on the flag dialog itself reads simply:

A reasonable person would find this content inappropriate for respectful discourse.

How do you know what constitutes respectful discourse? Pay attention to how folks converse, observe what they find respectful and what they find disrespectful, what causes offense and what does not. There are a few examples of rudeness in the help center, but these are neither exhaustive nor specific enough to rely on in every possible situation.
As always, you're free to ask questions here on Meta... But don't expect to be given immutable rules that you can apply without regard to context. As with nearly anything involving social interaction, objective rules are hard to find and universal ones are rare as hen's teeth. 

