I applaud the approach you have taken with most of the IG. Particularly in including a max binding for some of the value sets. Only problem is that you SHALL have HTA work with you to confirm/define the external code system identifier for all external code systems not already included in terminology.hl7.org (THO). Please work with HTA to get all the necessary information about whatever you mean by cancerstaging.org (which redirects to the main page at facs.org).