CRD, DTR and PAS are intended to be implementable independently. They have a shared use in that one of the uses for CRD is to indicate that prior authorization is necessary and one of the uses for DTR is to support the automated gathering of information to submit a prior authorization request. However, it's possible to implement PAS without using either CRD or DTR. Similarly, it's possible to use CRD and DTR for purposes that don't result in a prior authorization and/or to manage a prior authorization that results from CRD and DTR without using PAS (e.g. by using existing portal/fax/other mechanisms). We have agreed to provide a standard blurb that highlights the ways in which CRD, DTR and PAS can be used together and to highlight how the scope of each IG relates to the overall prior authorization workflow when used for that purpose. However, we don't want to tie the IGs together too tightly because they can be (and are) expected to be used independently in many cases. We will update language in each of the specifications to make clear that they can be used independently and (with the exception of PAS) they have significant scopes above and beyond performing prior authorization. This, together with the already agreed changes to make more clear how each IG can fit into the prior authorization workflow will hopefully make both their independent use and their cooperative use clearer.