I think my every-day carry keyring has enough space for a small piece of paper, which I could fill with personal information. What is the recommended wisdom on what to include? I am a bit concerned about ID theft.

At the moment my list falls into 3 groups: personal, legal and financial. The personal info includes my phone number, my next of kin's contact details, and my doctor's contact details. These are intended to be useful for identifying me if my EDC gets lost and whoever finds it wants to return it to me. Also, if my body is found dead they might as well know whose body it is, and if it is just unconscious they might want to get hold of my medical records. I am not sure whether I should include my postal address. It might be tantamount to telling burgulars which house is empty.

The legal info includes my passport number, my social security/national health number, and my driving licence number. But are these actually useful, eg if I were abroad and my passport got stolen? Or would it be enough to know my name, date and place of birth (which I have managed to memorise)?

Financial info is basically credit card numbers. I could include all the info needed for a "not present" transaction; it might be handy to be able to buy stuff even when everything else is lost/stolen. However, that seems really risky if the EDC keyring itself is stolen. Another option is to just include the card numbers, mainly so that I can cancel them if necessary. Perhaps with some light encryption, that I could undo in my head. Again, I am wondering if this stuff is really needed or whether the CC companies are used to people reporting lost cards without knowing the numbers.

I expect space to be very limited. I won't be including whole photocopies of passports etc. I am not sure about insurance numbers. I can see it makes sense to include them in a bug-out bag, but it hardly seems necessary in an EDC.

What does everyone else do? I don't recall it being mentioned in many PSKs, at least, not in detail. I suppose it's not really wilderness survival.