I refer with my question primary to length, based on bytes because a sign in UTF-8 can have 1-4 bytes.
Furthermore some special signs like control-signs might not be allowed. This question is related to bulk-creation of wallets, so it's not about my personal desire or needs but only about technical limitations.
Please, if you've any information about limited field-lengths in databases of exchange- or trading-platforms, that's welcome too as it's indirectly related to my question.
Also password limitations of any monero-related software are welcome.
I read the question beside answer related to "are there certain-characters unsuitable for passwords" but think that this question is no duplicate as it's more detailed.
The following related issues I found on github:
Own verifications still include much more signs which make some problems but due to the large amount of UTF-8 signs it's hard to make a list especially related to languages like Arabic, but others too.