Eurocard is a European standard format for PCB cards, which can be plugged together into a standardized subrack. The subrack consists of a series of slotted card guides on the top and bottom, into which the cards are slid so they stand on end, like books on a shelf. At the "back" of each card is one or more connectors, which plug into mating connectors on a backplane in the rear of the subrack. The eurocard measures 100mm by 160mm.
- Eurocard article on Wikipedia