Common Indexing Protocol
The Common Indexing Protocol (CIP) was an attempt in the IETF working group FIND during the mid-1990s to define a protocol for exchanging index information between directory services.
In the X.500 Directory model, searches scoped near the root of the tree (e.g. at a particular country) were problematic to implement, as potentially hundreds or thousands of directory servers would need to be contacted in order to handle that query.