[DR008] - passing arbitrary content

Current wording of DR008
Support passing arbitrary content from third parties (send digitally 
signed doc w/o touching data) [other than the mechanisms described under 
3.5 Data Representation]. 
Proposal
I am not sure what this requirement adds on top of DR040. This 
requirement appears to describe a possible application of the 
functionality described in DR040, not a separate and distinct 
requirement.  Therefore, I propose we strike this requirement from the 
document.