Dear Anne and all,
ASCII is a safe subset of UTF-8, an encoding method of Unicode characters. So having one mandatory representation in ASCII is technically reasonable way if source language field is suppoted, e.g.
GUID01+Flora of Japan ... + ja_JP GUID01+Nihon shokubutushi ... + ja_JP GUID01+(Nihon shokubutushi in Kanji)...
The first one is translation, the second one is transliteration, and the last one is original one. The last part ja_JP tell that these are non-original one. I suggest to add source language as an optional item to Level 1. The field may have list of languages if the publication is written in two or more languages, e.g. ICZN itself.
Note that here I gave the same GUID to all three representations of the single publication. It implies that the GUID is ID for the literature object, not for (meta) data objects. If we need GUID for data objects also, we would need two types ofGUID.
I meant ISO dates only for "date published (as corrected)". I agree with you date issue; in Level 1, date published as cited should be as is, shouldn't be interpreted.
Cheers, James