Currently, "address" is listed as a search parameter. I believe that there isn't sufficient information given for implementers regarding how to make this work well for patient queries.

A client application is rarely going to have a single field for user input for "address" rather, the client application may have a field for street address, postal code, city, etc.

From a server standpoint, a system is likely to have more than just one address. Also, attempting a match/filter a set of patient records based on street address lines is something that is unlikely to be supported. Lastly, when used in a search, address information is typically always referring to a patient's usual residence so it would be helpful if the specification made this clear in some way.

Suggestion: break out any address related search parameters to be more specific. etc. Include 1 or 2 of the most common items that might be included in a patient search and then allow individual implementations to add in any additional search parameters. e.g. instead of "address" have e.g. homeCity, homePostalCode.