Does the plain language of Federal Rule of Criminal Procedure 11(c)(1)(B) require that the government either join in or not oppose the defendant's sentencing request in plea bargains?

1. Does the plain language of Federal Rule of Criminal Procedure 11(c)(1)(B) require that the government either to join in the defendant’s sentencing request or to not oppose the defendant’s request when plea bargains are entered into pursuant to FRCRP 11(c)(1)(B) ? 2. May parties to a plea agreement contract for plea bargain provisions that violate s FRCRP 11(c)(1)(B) ?