It turns out here are additional street address standards, in addition to the URISA proposal that we discussed earlier. Joe Hall (UC Berkeley) emailed the following tip:

“… there is [xAL], the Extensible Address Language… for which a US-specific subset of the elements in that standard could be used (as a basis or as the standard itself).”

Joe also gave the url for xAL.

Thanks to Joe for the tip, and if there are others out there, please pass them along.