Reserve members are held to the same conditions and bylaws as the active members except they are not bound by the necessity to be on 24 hour call, nor are required to attend JLA meetings and they do not have voting rights. Reservists must have assisted the League on at least one mission. Reserve members are entitled to attend JLA meetings and are given signal devices. If a reservists misses three summons for help then they are removed from reserve membership.
In the classic League Zatanna started as a reservist and Metamorpho was another reservist. In the revised continuity Superman must also be counted as a League reservist for much of its history. Under the JLI reserve status was generally applied to heroes who assisted on mission a but were never part of a salaried group structure. This would include Superman, Wonder Woman, Captain Marvel and later the Batman.
Under the modern League reserve status is a little more fluid. Effectively any active mainstream DC hero who is not a member of another team could be considered a reservist. The fully reserve of the JLA is rarely called into action - most recently against Amazo (JLA #27) and during the JLA Verus Titans mini-series. Normally the JLA relies on a hand full of more select reservists including Steel, the Atom and Oracle. Reserve status was also conferred upon a young time travelling Hal Jordan when he visited this era.
Honorary membership is given to any hero who assists the League, but declines active or reserve membership. Honorary members have no duties, must go through an active member to contact the League and may attend social functions.
The original honorary member of the League was Snapper Carr, nephew of Simon Carr the League's funding liaison. Other honorary members of the classic League include Adam Strange, Batgirl, Sargon the Sorcerer, Green Lantern (John Stewart) and in pre-Crisis continuity Supergirl. There is, and always has been, a question over the membership of the Phantom Stranger. He was elected to active status in Justice League of America #103, but seems to have been unavailable for subsequent missions. This means that he would have automatically slipped into reserve status. The 1990 JLA Sourcebook lists him as an honorary member, but he seems to have been more than this.