Members of the same team may communicate between one another except during times where explicitly prohibited by the team format rules.
Players on a team may talk to their teammates at any time about nearly anything, with the below exception.
However, team members that have an opportunity to acquire hidden information (e.g. by speaking to spectators following their own match while a teammate is still playing), are restricted from communicating with teammates for the duration of that match.
Prohibitions against written notes of any kind during drafts apply to team drafts as well.
If a member of a team has access to hidden information from outside his or her teammate’s match, he or she must refrain from communicating with teammates who are still playing. Common occurances of this are during team events, once a player has stood up and moved around after their match they have the potential to see hidden information from their teammate’s opponents. This doesn’t mean the players can’t use the restroom once they are done with their match, but they should call a judge to direct them. Most times judges will direct players to walk to the restroom so they can confirm they aren’t trying to gain information.See MTR 8.3.