Official rule text
WORMHOLES KEY CONCEPT: CAPACITY Some system tiles contain wormholes. There are two types of The number of fighters and ground forces that a player basic wormholes–alpha and beta–as indicated by the wormhole’s has in the space area of a system cannot exceed the symbol. Systems that contain identical wormholes are adjacent combined capacity of that player’s ships in that system. to one another for all purposes. For example, if a player has two carriers in a system, each with a capacity of “4,” that player cannot have a combination of more than eight fighters and ground forces 40 in the space area of that system. Ground forces on planets do not count against this limitation. If at any time the number of a player’s fighters and ground Alpha Wormhole Beta Wormhole forces in the space area of a system exceeds the capacity of that players ships in that system, the excess units are ANOMALIES destroyed. During combat, a player’s fighters and ground Some system tiles contain anomalies. These systems restrict forces can exceed their ships’ capacity, but at the end of movement and have special rules governing them. the combat, any excess units are destroyed.