Clan Prestige is a Background in Vampire: The Masquerade, that reflects how well received a vampire is by his own Clan. Most vampire have only status in their own Clan, however, and something truly exceptional has to be done to earn the favour of another. Also, Clan Prestige does in no way ties into a vampires Status, a vampire can have a highly respected role within his Clan, but be despised by his sectmates.
Clan Prestige stems from the goodwill, fear and awe a vampire inspires in others of her clan, and the extent to which she has mastered the rules, values and idiosyncrasies of clan culture. In other words, it measures how well she has learned to play the games important to her clan. It affects how (or, indeed, if) any Clanmates will come to aid if she issues the call, how many will stand up for her, and how well she is able to shape the clan's internal politics.
Clan Prestige is gained by currying favor within the clan and, sometimes, by betraying members of the own sect. It is measured across the width and breadth of the clan, although more structured and unified Clans (like the Tremere or Ventrue) have a different approach to codifying this internal standing than more informal Clans (like the Gangrel or Malkavians). Each Clan has its own approaches on how to measure their internal prestige.
As all vampires are individuals first, and Clanmembers second, Clan Prestige rarely matters in the night-to-night affairs of a domain and only comes into play if there is a major gathering of the Clan. Much of the time, the ancestry of any given Kindred in a particular city is undisclosed – or, more simply, unknown. Internal quarrels make each Clan far from unified, although some like to spread the image of it.