from 

<h:div class="summary">The base of one or more links.</h:div>
<h:div class="description">On link elements the value is the single id of an element within the doc or context specified in map@fromRef attributes. It must identify the element uniquely. The reserved value 'null' implies that no mapping has been provided for the object(s) in the 'to' attribute. This implies no semantics but may be used by software to keep count of which elements have been mapped. For multiple targets use 'fromSet'.</h:div>
<h:div class="curation">2005-06-18: updated docs</h:div>

Attribute Information

Used By

Attribute Group from

Source 

<xsd:attribute id="att.from" name="from" type="refType">
  <xsd:annotation>
    <xsd:documentation>
      <h:div class="summary">The base of one or more links.</h:div>
      <h:div class="description">On link elements the value is the single id of an element within the doc or context specified in map@fromRef attributes. It must identify the element uniquely. The reserved value 'null' implies that no mapping has been provided for the object(s) in the 'to' attribute. This implies no semantics but may be used by software to keep count of which elements have been mapped. For multiple targets use 'fromSet'.</h:div>
      <h:div class="curation">2005-06-18: updated docs</h:div>
    </xsd:documentation>
  </xsd:annotation>
</xsd:attribute>

Sample