Use cases for discovery of data

I expect to be able to inquire about the presence of a datum without receiving the content of that datum. The GA4GH/Beacon project fulfills some of this requirement. Variant presence can be discovered from those sites participating in the Beacon network (and there is some discussion on expanding the Beacon approach to other data types).

But more broadly, there is also the need to be able to discover other GA4GH compliant servers. This ability begins with this effort.