Unity's first ten loss codes are validator failures and publisher blocks.

A Unity loss code in the 1000s never appears in the OpenRTB table. Unity Exchange returns it in ${AUCTION_LOSS} when the bid failed Unity's own checks before price mattered.

The first four are on the bidder. 1000 means Unity's OpenRTB validator rejected the payload. 1001 means the body was not JSON. 1002 is the catch-all marketplace block, the code Unity uses when it will not name a narrower rule. 1003 is specific: the advertised app's age rating is above the publisher's maximum.

The next six are publisher blocks, still on Unity's integers. 1004 and 1005 are crtype on a consolidated request: missing, or not one of the ad types Unity sent. 1006 is the region. 1007 is the platform, iOS or Android. 1008 is a sensitive attribute such as real-money gambling. 1009 is a Unity subcategory the publisher turned off.

The full list, including 1010 through the creative-review codes, is the Unity loss index.