Abstract: In a system which permits different components of a document to be linked, a unique token is associated with a change to data in the source of a link. The token is passed with a command to update linked data. Each destination object keeps track of the token associated with the last change made to its linked data. When a new command to update linked data arrives at the destination object, the token for that update is compared with the token for the previous update. If the tokens are the same, an alert is presented to the user to indicate that either the change has been propagated around a cycle, or more than one update path exists between the source object and the destination object. In response, the user can elect to prevent the change from being carried out in the destination object, in which case the cycle is broken. Alternatively, the user can elect to let the update continue, for example in those situations in which multiple update paths are desirable.