Abstract: System and methods for managing content modification messages are provided. In some embodiments, a request to send a modification message to a second user is received from a first user. The request to send the modification message pertains to a modification made to a first user-specific version corresponding to the first user and represented by a first delta. The modification message comprising a second delta is generated. The modification message includes second instructions to modify a second user-specific version to include the modification within the second user-specific version by resolving the first delta and the first user-specific version to the second user-specific version. A message indicator for the modification message is provides to a client device of the second user. The message indicator identifies the first user as the sender of the modification message.