<ptr>

<ptr> (pointer) defines a pointer to another location. 3.6 Simple Links and Cross-References 16.1 Links
Module core — 3 Elements Available in All TEI Documents
In addition to global attributes att.pointing (@type, @evaluate) att.declaring (@decls)
target specifies the destination of the pointer by supplying one or more URI References
Status Required
Datatype 1–∞ occurrences of 

<rng:ref name="data.pointer"/>
data.pointer
separated by whitespace
Values One or more syntactically valid URI references, separated by whitespace. Because whitespace is used to separate URIs, no whitespace is permitted inside a single URI. If a whitespace character is required in a URI, it should be escaped with the normal mechanism, e.g. TEI%20Consortium.
cRef (canonical reference) specifies the destination of the pointer by supplying a canonical reference from a scheme defined in a refsDecl element in the TEI header
Status Required
Datatype 1–∞ occurrences of 

<rng:ref name="data.word"/>
data.word
separated by whitespace
Values the value of cRef should be constructed so that when the algorithm for the resolution of canonical references (described in section 16.2.5 Canonical References) is applied to it the result is a valid URI reference to the intended target
Note
The refsDecl to use may be indicated with the decls attribute.
Currently these Guidelines only provide for a single canonical reference to be encoded on any given ptr element.
Used by
May contain Empty element
Declaration

<rng:element name="ptr">
 <rng:ref name="att.global.attributes"/>
 <rng:ref name="att.pointing.attributes"/>
 <rng:ref name="att.declaring.attributes"/>
 <rng:choice>
  <rng:attribute name="target">
   <rng:list>
    <rng:oneOrMore>
     <rng:ref name="data.pointer"/>
    </rng:oneOrMore>
   </rng:list>
  </rng:attribute>
  <rng:attribute name="cRef">
   <rng:list>
    <rng:oneOrMore>
     <rng:ref name="data.word"/>
    </rng:oneOrMore>
   </rng:list>
  </rng:attribute>
 </rng:choice>
 <rng:empty/>
</rng:element>
element ptr
{
   att.global.attributes,
   att.pointing.attributes,
   att.declaring.attributes,
   (
      attribute target { list { data.pointer+ } }
    | attribute cRef { list { data.word+ } }
   ),
   empty
}

<s:report test="@target and @cRef">the target and cRef
attributes are mutually exclusive.</s:report>
Example
<ptr target="#p143 #p144"/>
<ptr target="http://www.tei-c.org"/>
Note
The target and cRef attributes are mutually exclusive.