DIN 72552

DIN 72552 is a DIN standard for automobile electric terminals, standardizing many contacts in an automobile with a code.
This table gives most frequently used codes.
EN 50005.
A different standard, European Norm (EN) 50005 recommends terminal numbering for general application relays (e.g. 11/12/14/A1/A2 for a SPDT relay) that may nevertheless be applied to automobiles.