184. Intervention is either voluntary or forced.
Intervention is voluntary when a person who has an interest in a proceeding but is not a party or whose participation in a proceeding is necessary in order to authorize, assist or represent an incapable party intervenes in the proceeding as a party. It is also voluntary when a person wishes to intervene for the sole purpose of participating in argument during the trial.
Intervention is forced when a party impleads a third person so that the dispute may be fully resolved or so that the judgment may be set up against that third person. It is also forced when a party intends to exercise a recourse in warranty against the third person.