An apparatus for controlling printing or display of documents represented in a structured hierarchal page description language. Documents are provided as a document data stream which can include references to dictionary generators which can be incorporated into the document by the content processor. Documents are defined by a prologue section which may contain definitions and declaratory commands, with content portions containing specific tokens or commands for specific images. The document data stream has a hierarchal structure. A mechanism to provide dictionaries is provided which will process dictionary entries as if they were macros, where the dictionary entry becomes part of the original document data structure. The storage of the references to the dictionaries is accomplished in a tree-linked stack structure with a last in first out arrangement which allows for a faster search order of dictionaries. The tree-linked stack structure further allows for a correct identifier to be associated with a given reference thereto, even if different dictionaries within the document data stream might be present. The context of the document data stream and the level in which a call is made determines the dictionary which is being referenced. This provides a macro facility ability in a document data stream. Context declarations are processed in a similar manner to determine the context of declarations within the inputted document data stream.