Consider adding a datatype for standard identifiers for persons

[benjamingeer]

I was talking to someone who works on metadata at the BnF, and she said they use ISNI identifiers for persons. For example, here's their record on Marcel Proust:

https://catalogue.bnf.fr/ark:/12148/cb119207126

It refers to this ISNI representing Proust:

http://isni.org/isni/0000000121003911

Some interesting information about ISNI](http://www.bnf.fr/en/professionals/isni_about.html) on the BnF's web site.

The person I spoke to mentioned that Google (via YouTube) has decided to use ISNI.

I believe BEOL uses GND and VIAF identifiers. I think Knora provide built-in support for these sorts of identifiers, perhaps by adding a new datatype.