While looking up sources on tznius (there are not many) i was pointed by the mishna berura to kesubos 72a-b which discusses a number of issues for which a woman may be divorced without a kesuba payment.

My question centers around the curious observation that everything on in the mishnah, as explained by the gemorah, consists of information that could not be readily gleaned about an unmarried woman, and indeed the halacha is that if a woman is in violation of one of these sorts of things before hand, one is not entitled to a divorce, because it is presumed you decided that you could live with it. (I can't give you the source, sorry.)

There are two theoretical exceptions: talking to men in the market, and covering ones upper arm. (never mind the context seems to imply ones whole arm.) if it is indeed incumbant upon a woman to follow these rules before marriage, since they have to be done in the market place in order to qualify, then would it not follow that if this is the case, he would have known that she does so and how could he be then entitled to a divorce?

or perhaps this is indeed just like covering the hair (which is mentioned here biblicaly ONLY applies to a tiny, token covering, such as a basket might cover if she put it on her head, and such a [tiny] kipah is perfectly valid midoraisa) and is only incumbant upon married women?

It isn't usualy the derech of a woman to suddenly start uncovering her upper arms in the market, when she wasn't accustomed to do so before, and if you knew, then could you not send her out?

I'm curious what various people here think, especialy melech and krebbe.

(and no, I've not looked at the rishonim or achronim on this. my arameic is not the best, and while I can read most halachic works fine, including the mishnah, at least with minor help from a dictionary, I cannot read things that use to much arameic very readily. in particular the rosh's and maharsha's language is difficult.)