A character with this skill may, on completion of a successful Test against their Int, be assumed to know the details of another noble's family saga. This should include knowing which faction(s) the character's family supports, their famous forebears, their current standing, etc. A modifier of +10% should be applied to tests concerning NPCs of Noble rank 4 or above. If the character makes a particularly successful roll (with 30% to spare), he will also know some secret about the other character's family. If the test is failed, the character's background remains a mystery. If failed by more than 20%, then you've made a real mistake and got the guy crossed with somebody else.
For example, Baron Wilhelm von Michelin, a PC Noble (Rank 3) is living at the Electoral Court in Nuln, looking to ingratiate himself and gain an important military command. However, a rival for the post is Duke Feuerberg and he shows no sign of being ready to hand over the reins. Wilhelm, not wanting to be seen asking a lot of questions, racks his memory to see what he knows of the Feuerberg family - his player rolls 21% against his current Int of 49%. Because Feuerberg is a Rank 4 Noble, the 10% bonus means Michelin's player is aware of a little-known fact about the Feuerberg clan - the gamesmaster decides that he has heard of bad blood between the Feuerbergs and the Halflings of The Moot. Perhaps the Duke has plans to use the troops which the post would place at his command to settle this old grudge - or perhaps Michelin can just make people at court think this is what he intends...