What are the rules for volunteering on dependent visa like h4 or f1 etc?

hi Gals

I have a question about helping someone on a H4 or any dependent visa.

What are the stipulations of legal and illegal voluntary work?

I understand some stipulations

1. We can not volunteer there if it gifts, money, future job is promised.
(However, what if we volunteer there and after we get employment authorization we apply for a job there and happen to get hired, that's different I hope?)

2. I heard we can not volunteer if the volunteership is to be used as professional experience or on a resume.
(This to me seems like a grey area and really doesn't make much sense. In America, Americans are not shy about noting volunteer work on a resume, in fact it helps a resume stand out from the rest. Please explain this.)

3. We can not volunteer if the timings are too strict.
(A volunteer post should not 'fire' us if we don't come in regularly, etc. I understand that, but if there is no structure, how can it be productive or be worth our while?)

4. We can't volunteer for a position that someone usually gets paid for. We have to give it up or never take it if it takes a paid job away from someone else.
(I understand this one. Makes sense for American citizens as well as others.)


Please help clarify this so I can help my clients, friends and others better.

Thanks.
Jennifer Kumar