1. A method of processing a hierarchically structured page description language document, comprising the steps of: creating a primary data structure which is a stack, wherein each hierarchical level of the document has a corresponding level in the stack; inputting an element indicating a beginning of a hierarchical level A of the document; creating a plurality of references for a level A in said primary data structure, said plurality of references for the level A being used to keep track of parameters of the hierarchical level A of said document including a reference used for keeping track of dictionaries which are used during processing of the document, said dictionaries including key-value pairs; inputting an element at the hierarchical level A indicating a predefined dictionary is to be used during processing of the document; changing the reference used for keeping track of dictionaries to refer to said predefined dictionary; inputting an element indicating a beginning of a hierarchical level B of the document which is below the hierarchical level A in the hierarchical structure of the document; and creating a plurality of references for a level B in said primary data structure which is different from the level A in said primary data structure, said plurality of references for the level B being used to keep track of parameters of the hierarchical level B of said document including a reference used for keeping track of dictionaries which are used during processing of the hierarchical level B of the document, said plurality of references for the level B being equal to said plurality of references for the level A when said plurality of references for the level B are created; wherein the level A in said primary data structure which is a stack is pushed into the stack before the level B is pushed into the stack; and wherein said plurality of references for the level A comprises a reference in said stack to a plurality of subsequent references, and said reference in said plurality of references for the level A which is used for keeping track of dictionaries includes a reference from said stack to said plurality of subsequent references and one of said plurality of subsequent references refers to said predefined dictionary.