Merge pull request #354 from handrews/pfmt

Clarify what is meant by JSON Pointer format.

Author: handrews

jsonschema-validation.xml

@@ -890,8 +890,10 @@
                         This attribute applies to string instances.
                     </t>
                     <t>
-                        A string instance is valid against this attribute if it is a valid JSON Pointer,
-                        according to <xref target="RFC6901"/>
+                        A string instance is valid against this attribute if it
+                        is a valid JSON string representation of a JSON Pointer,
+                        according to
+                        <xref target="RFC6901">RFC 6901, section 5</xref>
                     </t>
                 </section>
             </section>