Oracle Master

Oracle Master is a Covenant Sangheili rank. It is not given to members of the Covenant military and thus is currently the only known "civilian" title for Elites.

Rank
Oracle Master seems to be an office of duty among the Covenant High Council - usually an Elite particularly knowledgable in affairs is made the personal adviser of a Hierarch. Oracle Masters also serve aboard ships, serving as data gatherers.

The only known Oracle Master, Parala 'Ahrmonro, is described as old, but fiercely intelligent. Beyond that, little else is known about the rank, or the Elite who holds it, other than that he collects intelligence.

It is possible that Oracle masters are supposed to ask Oracles like 343 Guilty Spark questions and gather information from them. Take note that this is purely speculation and is not mentioned anywhere.