Update useconstraints.asciidoc

Changed references from data to data resource, and confirmed all encoding guidelines refer to MD_LegalConstraints rather than just LegalConstraints. Fixes #122

docs/partials/useconstraints.asciidoc

@@ -11,7 +11,7 @@ include::includes/partials-attributes.adoc[]
 resource
 
 |Purpose and meaning |The purpose of this element is to describe any
-restrictions on usage of the data (as opposed to access)
+restrictions on usage of the data resource (as opposed to access)
 
 |Obligation |Mandatory
 
@@ -88,7 +88,7 @@ Limitations on public access
 recommends using Limitations on public access for these
 . The useConstraints element shall contain an MD_RestrictionCode element
 with code list value "otherRestrictions"
-. The LegalConstraints element shall also contain a gmd:otherConstraints
+. The MD_LegalConstraints element shall also contain a gmd:otherConstraints
 element, with free text.
 . "No conditions" and "conditions unknown" shall be specified using a
 gmx:Anchor link to the relevant entry in the INSPIRE metadata registry,