Protocol buffer: does changing field name break the message?

With protocol buffer, does changing field name of a message still let it compatible backward? I couldn't find any cite about that.

Eg: original message

message Person {
  required string name = 1;
  required int32 id = 2;
  optional string email = 3;
}

Change to:

message Person {
  required string full_name = 1;
  required int32 id = 2;
  optional string email = 3;
}