[VCARDDAV] Questions about text handling in vCard 4.0 (rev 11)

[Daisuke Miyakawa <[e-mail]>]

Hi vCard experts,

Now I'm confused with how to decode characters with backslash in a text
field, like '\t'.

4.1. in vCard 4.0 shows how to encode some characters like line break and
comma, but there's no mention about the following topics developer may
encounter.
- how a receiver accept string with backslash which is not determined in the
spec (e.g. How "\t\h\i\s\ \i\s\ \a\ \t\e\s\t\n" should be decoded if the
receiver happened to see it?)
- how to handle invisible/control characters valid in Unicode (e.g. tab,
full-width space used in Japanese, etc.) It can be held as is, but I think
it might be better to encode it to something like \xXXXX only when it is not
readable enough.
- How to handle ',', '\,', ';', and '\;' in X- properties (e.g.
"X-EXTRA-SORT-STRING:This,is\, a\;test;\, isn't\;it?"). What to do when some
sender wanted to use splitter (',' or ';') in vCard 4.0.

Thanks,

-- 
Daisuke Miyakawa (宮川大輔)
[e-mail]