[thinkpad20]

I don't think that's a major issue. It should be straighforward to disambiguate: make separate units for imperial pint, liquid pint, dry pint, etc. If this is cumbersome, provide an option to set aliases for these in a meta tag, for example. If the writer of the document is sophisticated enough to be using these tags, they should be sophisticated enough to look up what the proper name is for the unit they're using.