You cannot call a rematch. You can only check for those who wants to rematch and you can call them. Sometimes, you can also receive calls (Even if you are urgent to do something or if the battery is low).
Yes, but they have to want the rematch. your pokenav has a feature called match call that lets you know when a trainer wants a rematch. There will be a box with a pokeball design on it next to the name of the trainer (or gym leader).
I believe you can get the rematch with Steven in emerald by battling the Elite four again.After that you can battle Steven.
In Pokémon Emerald, match call trainers can be found throughout the Hoenn region. You can receive calls from trainers you've battled previously, and they can be located in various locations, such as towns, routes, and even in Pokémon Centers. To find them, you can use the Match Call feature on your PokéNav, which allows you to see which trainers are available for a rematch. Notably, some trainers become available for rematches only after certain conditions are met, such as time or the player’s progress in the game.
The gyms won't re-open until you've defeated the Elite Four. Afterwards, check Trainer's Eyes [Sapphire/Ruby] or Match Call [Emerald] on your Pokenav. When a gym leader is ready for a rematch, a pokeball will appear next to their name, and you can go challenge them again.
At any random time..actually..keep calling them in ur pokenav!
its all ready there
In Pokémon Sapphire, the Match Call feature is accessed through the PokéNav. After obtaining the PokéNav from your rival, you can use the Match Call function to challenge trainers you've previously battled. To do this, simply select a trainer from your list and call them for a rematch. You can find the PokéNav in your bag, and the Match Call option will be available once you've battled trainers in the game.
there's no match call in ruby and sapphire it's only in emerald
No, this feature is only available in Pokemon Emerald.
some trainers will register themselves in your poke-nav. after talking to them, and will bleep/call you for a rematch.
There isn't any...you get a rematch by getting people's phone numbers then sometimes they call for a rematch.
Only on Pokemon emerald can you rematch gym leaders just wait patiently until they want to rematch you then go to there gym find them and battle them.