What is a composite baseline in UCM and when will it be used?

Composite Baselines Reference: Guidelines for Using Composite Baselines in UCM .

Introduced in ClearCase v2002, compound baselines are a mechanism for grouping baselines into a collection. One baseline is designated as a compound, and the other baselines become members of the compound

You don't need to use compound baselines if you have multiple components, but:

If you want to remember a set of baselines that exist at a given point in your flow , it is helpful to have a bottomless component that can record the baseline of its member.

In theory, you can have "composites of composites":

I would not recommend, however, because of the " baseline parasite levels (explained briefly here and here )