Hi Tobias, Gary and others,
in principle each function, that generates (new) collections, could be
used. For example from a given collection one could build a new
collection by requiring restrictions like for example time constraints
on the generation of the DOs it contains. Or one can build a kind of
power collection, the collection of all sub collections.
Particularly interesting generation rules come with the possibity of
following the links given in the collection, either by the PIDs in the