1. A method for managing document annotations in a publish/subscribe system as carried out at a subscribing system, comprising: subscribing a user to annotations of a document, wherein each annotation is separate from the document and includes reference to display of the annotation in relation to display of the document; defining a role of the subscribing user, wherein use permissions of a set of the annotations by the subscribing user are controlled based on the role, the use permissions including access permissions based on at least one constraint selected from a group consisting of a time constraint and a location constraint of the subscribing user; and filtering, using at least one tag, the subscription of the subscribing user to the set of the annotations based on a publishing user.
2. The method of claim 1 , wherein the access permissions based on the at least one constraint include subscription access permissions including subscription access based on at least one item selected from the group consisting of the time constraint and the location of the subscribing user.