Hello!

I know there are several different schemas being used by different programs to store faces in a photo's metada.
Adobe Photoshop, Google Picasa, Windows Live Photo Gallery use each different ways for it.
I don't know how Windows Photo, ACDSee and others do it, but whatever program I try out, they all start with blank faces and are ignorant of what is already tagged.

What I have seen is that nearly none of these programs is able to read another program's face tags.
Picasa can read WLPG tags, but no the other way round.

So, now my questions:

Which schemas is digikam able to read?
Which schema does digikam use to store its faces to tags?

Where is the documentation for that?
Is there a roadmap for fostering any kind of interoperability?

Thank you very much in advance!