1. A rights expression system for facilitating creation and/or modification of rights expressions in a rights expression language (REL) based on one or more schemas, said rights expression system comprising: one or more layouts selectable by a user of said rights expression system, each layout corresponding to a rights granting paradigm, each layout comprising: one or more type selectors selectable by the user, each type selector being adapted to present one or more REL terms associated with a selected type selector; and one or more input forms associated with said one or more REL terms which are invoked based on a REL term selected by the user, said one or more input forms allowing input of a parameter required by said selected REL term; and a data engine that generates rights expressions in proper REL semantics defined by said one or more schemas based on said selected layout and parameter inputted by the user.