9. The structural matching engine of claim 4 having an intelligence to handle queries which require all tokens which are structurally under a start token, wherein the intelligence to handle queries includes setting of a flag for all TIDNs and their descendents corresponding to that start token.
4. The structural matching engine of claim 1 , wherein the stack structure is a walker stack and wherein stacks of the stack structure are added for each start token of a message being processed and stacks of the stack structure are removed for each end token of the message being processed.