Record locator

A record locator is an alphanumeric code, typically 6 characters in length, used in airline reservation systems to access a specific record. When a passenger, travel agent or airline employee refers to a record locator they typically mean a pointer to a specific reservation which is known as a Passenger Name Record or PNR. However, a record locator can point at records containing other forms of data. Record locators are unique within a given system at a specific point in time. Because the number of character combinations in 6 characters is finite (albeit very large) record locators get reused once the data to which it refers has been purged from the system. Because 1, I and L can be confused (also 0 and o) these characters are not always used in record locators. The pool of available character combinations is further reduced because the locator is actually a location address and there are rules about what character combinations can be used for such addresses.