Which password limitations do exist?

Question

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.

UPDATE:
The following related issues I found on github:

• https://github.com/monero-project/monero-gui/issues/653
• https://github.com/monero-project/monero-gui/issues/883
• https://github.com/monero-project/monero/issues/938

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.

Answer 1

Since your question is not a duplicate of that other one as it's more detailed, my answer will just be a part of the the answer to that other one:

There is no length requirement (within reason - don't go using 4 billion character password or you'll run out of memory, and there might be a standard C++ library string limit, but if there is, it's likely pretty high).