All systems that can support wormholes have a hidden wormhole class. The wormhole class of a system determines which wormholes can lead to it. Some classes are visible by examining the region of the system and analyzing the region letter's position in the alphabet. The wormhole class of each system can be found in the Static Data Export.
- Prior to 2009's Apocrypha expansion, wormhole classes did not exist. After the expansion, the six different tiers of Anoikis' wormhole space were given classes 1~6.
- Because the wormholes introduced in Apocrypha could point at New Eden, three additional classes were required for High, Low, and Null security space. These are classes 7~9.
- Jove space does not accept wormholes, but was collectively given classes 10~11 anyway.
- Rhea also added 25 small shattered class 13 Anoikis systems.
- 2018's Abyssal space added classes 19~23, despite not accepting wormholes. These five classes are thought to correspond to the 5 different effect types, not the 7 different tiers of Abyssal space, but it is unknown what the true purpose of Abyssal space wormhole class categorization is.
- There is, or was, only one class 24 system, named Penalty. Probably used by GMs to quarantine cheaters.
- Zarzakh does not accept wormholes and does not have a wormhole class.
- These Thera-like lowsec systems already have a wormhole class: lowsec, so their reverse statics are likely hard coded to the system, unlike Thera.