You very nearly never know which version of a character set a sender or receiver uses or requires, and even for documents, the best you can tell is which version(s) (plural) of a given character set a text can be encoded in. You can't tell whether any edits to a document that would require one of the newer versions would still be acceptable or not to the originator.
Yep. (I wasn't meaning to encourage use of older versions for outgoing communication.) – The use case I have in mind is a passive one: having an easy way, in a few clicks, to fix a text that looks slightly odd without me having to do the work of researching older versions of codepages myself.
Stephan
