Re: addressable identifier?

I think you were initially in the "others" Romain, but not by the end of
the conversation where you clearly understood the difference that I made
between "start" and "self" links.

IMO the use case for an identifier is simple: we want to uniquely identify
a WP. For instance if I add multiple WP in a UA, this is the identifier
that the UA will rely on internally to associate various attributes and
settings to a WP.

The URI of a primary resource can't uniquely identify a WP, since it can be
present in multiple WP. That's not the case of a manifest, which is unique
to a WP.