1. A non-transitory computer-readable storage medium comprising a plurality of instructions to be executed in a computer for versioning of tags, the plurality of instructions comprising: instructions to receive information identifying a new first value of a first attribute of a tag applied to an object comprised among a plurality of objects in a memory of the computer, the information identifying no change to existing values of other attributes of the tag; wherein the object is of any type selected from at least a message type, a document type, a contact type, a discussion type, or a meeting type; wherein the other attributes are different from the first attribute; instructions responsive to receipt of the information, to automatically create for the object an incremental tag application comprising the new first value for the first attribute of the tag applied to the object and lacking the existing values of the other attributes of the tag applied to the object; instructions to automatically store in the memory, the incremental tag application in association with existing metadata comprising a full tag application to the object, the full tag application comprising an existing second value of a second attribute and an existing first value of the first attribute; instructions to receive a command to retrieve a current tag application for the object; instructions responsive to receipt of the command, to automatically prepare the current tag application by at least: retrieving the incremental tag application, retrieving the full tag application, and constructing the current tag application to comprise the new first value for the first attribute retrieved from the incremental tag application and the existing values of the other attributes retrieved from the full tag application; and instructions to automatically store in said memory, said current tag application.