Merge pull request #1435 from json-schema-org/gregsdennis/locatable-iri-adjustments

Gregsdennis/locatable iri adjustments

Author: gregsdennis

jsonschema-core.md

@@ -1167,9 +1167,8 @@ provides the ability to validate recursive structures through self-reference.
 
 The resolved IRI produced by these keywords is not necessarily a network
 locator, only an identifier. A schema need not be downloadable from the address
-if it is a network-addressable URL, and implementations SHOULD NOT assume they
-should perform a network operation when they encounter a network-addressable
-IRI.
+if it is a network-addressable URL. Implementations which can access the network
+SHOULD default to operating offline.
 
 ##### Direct References with `$ref` {#ref}
 
@@ -1299,17 +1298,19 @@ The use of IRIs to identify remote schemas does not necessarily mean anything is
 downloaded, but instead JSON Schema implementations SHOULD understand ahead of
 time which schemas they will be using, and the IRIs that identify them.
 
-When schemas are downloaded, for example by a generic user-agent that does not
-know until runtime which schemas to download, see [Usage for
-Hypermedia](#hypermedia).
-
 Implementations SHOULD be able to associate arbitrary IRIs with an arbitrary
 schema and/or automatically associate a schema's `$id`-given IRI, depending on
 the trust that the validator has in the schema. Such IRIs and schemas can be
 supplied to an implementation prior to processing instances, or may be noted
 within a schema document as it is processed, producing associations as shown in
 {{idexamples}}.
 
+Implementations MAY provide functionality to automatically fetch schemas based
+on location semantics expressed by the IRI, however such functionality SHOULD be
+disabled by default to prefer offline operation. When schemas are downloaded,
+for example by a generic user-agent that does not know until runtime which
+schemas to download, see {{hypermedia}}.
+
 #### Detecting a Meta-Schema
 
 Implementations MUST recognize a schema as a meta-schema if it is being examined