Multiple instances of protection from the same quality on the same permanent or player are redundant.
May 3, 2019 · War of the Spark
Some Auras both give the enchanted creature protection and say “this effect doesn’t remove” either that specific Aura or all Auras. This means that the specified Auras can legally enchant that creature and aren’t put into their owners’ graveyards as a state-based action. If the creature has other instances of protection from the same quality, those instances affect Auras as normal.
January 25, 2019 · Ravnica Allegiance
Some Auras both give the enchanted creature protection and say "this effect doesn't remove" either that specific Aura or all Auras. This means that the specified Auras can legally enchant that creature and aren't put into their owners' graveyards as a state-based action. If the creature has other instances of protection from the same quality, those instances affect Auras as normal.
January 23, 2015 · Fate Reforged
Some Auras both give the enchanted creature protection and say “this effect doesn’t remove” either that specific Aura or all Auras. This means that the specified Auras can legally enchant that creature and aren’t put into their owners’ graveyards as a state-based action. If the creature has other instances of protection from the same quality, those instances affect Auras as normal.
September 25, 2014 · Khans of Tarkir
Some Auras both give the enchanted creature protection and say “this effect doesn’t remove” either that specific Aura or all Auras. This means that the specified Auras aren’t put into their owners’ graveyards as a state-based action. If the creature has other instances of protection from the same quality, those instances affect Auras as normal.