BIND and DAV:checkout-set property

Does a checked-out resource appear in the DAV:checkout-set property of the
version only *once* or with all its mappings?

I.E.: If the checked-out resource is mapped to URI-1 and URI-2, what's true,
a) or b) ?

a) both URIs appear in the DAV:checked-out property value of the version
b) only one URI appears (server-defined)

Same question for other <href> valued properties, e.g.
DAV:workspace-checkout-set.

Our server forbids multiple mappings for history and version resources, so
properties like DAV:checked-out or DAV:version-history are not a problem in
our case.  

Regards,
Peter