When you promote a dataset to Discovery for enrichment, you will be able to define how much information another user can see on how your data intersects.

A full listing will enable another party to understand how your dataset intersects with theirs. This includes both the key overlap, and information about any categorical data. 

Selecting a full listing is recommended if you don’t mind who can learn from your data, for example this is likely the case if you are a data owner and want potential customers to be able to evaluate whether your data could be of use.