Clarify non-HTTP usage in generic terms.

Add some wording about request formats being defined in terms
of the target representation or not.  This should provide more
guidance for when "method": "post" and "schema" are relevant,
independent of URI scheme.

Author: handrews

jsonschema-hyperschema.xml

@@ -873,18 +873,25 @@ GET /foo/
                         This property specifies that the client can construct a templated query or non-idempotent request to a resource.
                     </t>
                     <t>
-                        If "method" is "get", the link identifies how a user can compute the URI of an arbitrary resource. For example, how to compute a link to a page of search results relating to the instance, for a user-selected query term.
+                        If "method" is "get", the link identifies how a user can compute the URI of an arbitrary resource.
+                        For example, how to compute a link to a page of search results relating to the instance, for a user-selected query term.
+                        Note that <xref target="hrefSchema">"hrefSchema"</xref> offers a superset
+                        of this functionality independent of the value of "method".
                     </t>
                     <t>
-                        If "method" is "post", the link specifies how a user can construct a document to submit to the link target for evaluation.
+                        If "method" is "post", the link specifies how a user can construct
+                        a document to submit to the link target for evaluation.
+                        This option is used for requests requiring a payload that is not described
+                        in terms of the target representation, since the target
+                        representation is described by <xref target="targetSchema">"targetSchema"</xref>.
                     </t>
                     <t>
                         Despite being named after HTTP's GET and POST, the presence,
                         absence, or value of this keyword does not impose any constraints
                         on either the method or protocol used to interact with the remote resource.
                         In particular, the same Link Description Object may be used
                         for multiple protocol methods.  For protocol methods whose
-                        request format is described by <xref target="targetSchema">"targetSchema"</xref>,
+                        request format is based on the target representation,
                         if "method" is "post" then <xref target="schema">"schema"</xref> is ignored.
                     </t>
                     <t>
@@ -943,6 +950,8 @@ GET /foo/
 
                     <t>
                         This is a separate concept from the <xref target="targetSchema">"targetSchema"</xref> property, which is describing the target information resource (including for replacing the contents of the resource in a PUT request), unlike "schema" which describes the user-submitted request data to be evaluated by the resource.
+                        "schema" is intended for use with requests that have payloads that are not
+                        defined in terms of the target representation.
                     </t>
                 </section>
             </section>