Status Loot or status items are documents, relics, scrying stones and amulets that various sentient monsters hoard. When killed, they may drop one of these status items, which may then be sold to certain city guilds to obtain personal and guild status points.
Status items are sold to city adventure guilds to obtain status points. There are four adventure guilds in each city; Fighter, Mage, Priest, and Scout. Each guild will only give you status for their matching type of status item. In addition to gaining personal status points for selling these items to the correct guilds, your guild will receive 10% of your gained status, towards the guild level. So, if you sell a status item that is worth 200SP, your guild will receive 20SP.
UPDATE: As of LU38, your guild will only receive status points for items if the guild is lower than the item's tier. For example, for Tier 5 items your guild must be less than level 45 in order to receive credit. Regardless of the guild's level, you will always receive personal status points. You can visually confirm what type(s) of status you will be awarded by looking at the status part of sell price at the merchant. Blue numbers will give both you and your guild status, yellow will only be only awarded to you.
When selling items in Qeynos and Freeport there are multiple NPCs to sell to in each Guild area. (This is left over from a time long ago when each tier's items had to be sold to a specific NPC) For simplicity's sake, the easiest ones to get to are the ones that are listed below. Additional changes to the game let you sell any guild's items to any guild, similar to how city merchants reward you for any type. Just find a merchant that gives status for them, and unload all of them!
In Kelethin each guild only has one status buyer. The NPC will have a variation of the tag <Relic Hunter>. You can also sell all status items to the City Merchants (Aothis and Celea Warmbreeze) at the Kelethin First Regional Bank.
In Neriak, City of Hate, You can sell all status items (regardless of type) to T'Roveus M'Otal in Blind Fish Hall (Guild Services) in Dockside Market ( -103, 8, 319 ) /waypoint -103, 8, 319.
In Frostfang Sea, You can sell all status items (regardless of type) to Mistress Thora in New Halas Storage and Containment ( 90, 149, -93 ) /waypoint 90, 149, -93, on the western side of New Halas.
In Maj'Dul, there are Faction Merchants inside the faction locked Courts (e.g., Coin Faction Merchant inside the Court of Coin instance) that will buy all your status items (regardless of type).
Across the Destiny of Velious zones, the various faction merchants for each group (Otters/Gnolls/Coldain/Ry'Gor) will also guy any of the items. (Note: this is the faction merchant, the one that sells adorns and armor, and not the NPC that sells you faction for Cloudy Gems.)