Existing Wording: One common operation performed with resources is to gather a collection of resources into a single instance with containing context. In FHIR this is referred to as "bundling" the resources together. These resource bundles are useful for a variety of different reasons, including:

Returning a set of resources that meet some criteria as part of a server operation (see RESTful Search)

Returning a set of versions of resources as part of the history operation on a server (see History)

Sending a set of resources as part of a message exchange (see Messaging)

Grouping a self-contained set of resources to act as an exchangeable and persistable collection with clinical integrity - e.g. a clinical document (see Documents)

Creating/updating/deleting a set of resources on a server as a single operation (including doing so as a single atomic transaction) (see Transactions)

Storing a collection of resources

Comment:

It isn't clear that there is a benefit from the different Bundle types using the same resource. There is limited overlap between the elements that make sense for one bundle type vs. another (as evidenced by the number of constraints). Request is only appropriate for transactions, search is only appropriate for search results, etc.Significant consideration should be given to splitting Bundle into multiple focused resources; some of these new resource may not even need to be persisted.

Summary:

Benefit of polymorphic bundle behavior unclear