Ghosting
Provided by the ASK Keyboard Dictionary
Aka/also known as: unmanageable key combinations, phantom keys
If a keyboard is said to experience "ghosting", it means an attempted key combination results in additional keys being registered when they're not actually pressed. Ghosting is a symptom of a keyboard using ohmic sensing on a key-matrix without diodes, as such keyboards allow for uncontrolled flow of electricity when more than two keys are pressed. The presence of ghosting is the main technical reason for a keyboard being limited to 2-key rollover. The effects of ghosting can be mitigated if the keyboard's controller electronics employ blocking.