label 

<h:div class="summary">A text string qualifying an object.</h:div>
<h:div class="description">A label can be used to identify or distinguish elements, add keywords or classifications and similar processes. It is usually interpretable by domain-aware humans (e.g. C3'-endo, but not a34561). It is usually either built in a semantically rich fashion (e.g. C2'-alpha-H) or belongs to a controlled vocabulary. It is possibly accessed by software in a domain-specific manner. It differs from
  <h:tt>description</h:tt>which is free text. The distinction between titles, names and labels is fuzzy, but we think this is worth making. Labels may be necesssary to identify objects within programs, while names are more likely to be reserved for database searches. Titles are likely to be freer text and not recommended for precise object retrieval.</h:div>
<h:div class="note">Labels should not contain whitespace. Punctuation marks are often necessary, but should not be gratuitously used. Punctuation clashing with XML character entities should be avoided; if this is not possible it should be escaped.</h:div>
<h:div class="example" href="label1.xml">
  <h:em>From IUPAC Dictionary of Medicinal Chemistry</h:em>
</h:div>

Element Information

Model

anyCml | ANY element from ANY namespace OTHER than 'http://www.xml-cml.org/schema' | ANY element from LOCAL namespace 'No Namespace'
Children: anyCml

Attributes

QName Type Fixed Default Use Inheritable Annotation
dictRef namespaceRefType optional 
<h:div class="summary">A reference to a dictionary entry.</h:div>
<h:div class="description">Elements in data instances such as _scalar_ may have a
  <h:tt>dictRef</h:tt>attribute to point to an entry in a dictionary. To avoid excessive use of (mutable) filenames and URIs we recommend a namespace prefix, mapped to a namespace URI in the normal manner. In this case, of course, the namespace URI must point to a real XML doc containing _entry_ elements and validated against STMML Schema.
  <h:p>Where there is concern about the dictionary becoming separated from the doc the dictionary entries can be physically included as part of the data instance and the normal XPointer addressing mechanism can be used.</h:p>
  <h:p>This attribute can also be used on _dictionary_ elements to define the namespace prefix</h:p>
</h:div>
<h:div class="example" href="dictRefGroup1.xml"/>
id idType optional 
<h:div class="summary">A unique ID for an element.</h:div>
<h:div class="description">Id is used for machine identification of elements and in general should not have application semantics. It is similar to the XML ID type as containing only alphanumerics, '_', ',' and '-' and and must start with an alphabetic character. Ids are case sensitive. Ids should be unique within local scope, thus all atoms within a molecule should have unique ids, but separated molecules within a doc (such as a published article) might have identical ids. Software should be able to search local scope (e.g. all atoms within a molecule). However this is under constant review.</h:div>
objectClass xsd:string optional 
<h:div class="summary">The class of an object.</h:div>
<h:div class="description">The type of this information. This is not controlled, but examples might include:
  <h:ul>
    <h:li>label</h:li>
    <h:li>summary</h:li>
    <h:li>note</h:li>
    <h:li>usage</h:li>
    <h:li>qualifier</h:li>
  </h:ul>It might be used to control display or XSL filtering.</h:div>
<h:div class="note">The attribute is named 'objectClass' to avoid clashes with other class attributes and inappropriate conversion to foo.getClass().</h:div>
value xsd:string optional 
<h:div class="summary">Value of a scalar object.</h:div>
<h:div class="description">The value must be consistent with the dataType of the object.</h:div>
Wildcard: ANY attribute from ANY namespace OTHER than 'http://www.xml-cml.org/schema'

Source 

<xsd:element name="label" id="el.label" substitutionGroup="anyCml">
  <xsd:annotation>
    <xsd:documentation>
      <h:div class="summary">A text string qualifying an object.</h:div>
      <h:div class="description">A label can be used to identify or distinguish elements, add keywords or classifications and similar processes. It is usually interpretable by domain-aware humans (e.g. C3'-endo, but not a34561). It is usually either built in a semantically rich fashion (e.g. C2'-alpha-H) or belongs to a controlled vocabulary. It is possibly accessed by software in a domain-specific manner. It differs from
        <h:tt>description</h:tt>which is free text. The distinction between titles, names and labels is fuzzy, but we think this is worth making. Labels may be necesssary to identify objects within programs, while names are more likely to be reserved for database searches. Titles are likely to be freer text and not recommended for precise object retrieval.</h:div>
      <h:div class="note">Labels should not contain whitespace. Punctuation marks are often necessary, but should not be gratuitously used. Punctuation clashing with XML character entities should be avoided; if this is not possible it should be escaped.</h:div>
      <h:div class="example" href="label1.xml">
        <h:em>From IUPAC Dictionary of Medicinal Chemistry</h:em>
      </h:div>
    </xsd:documentation>
  </xsd:annotation>
  <xsd:complexType>
    <xsd:choice minOccurs="0" maxOccurs="unbounded">
      <xsd:element ref="anyCml"/>
      <xsd:any namespace="##other" processContents="lax"/>
      <xsd:any namespace="##local" processContents="lax"/>
    </xsd:choice>
    <xsd:attributeGroup ref="id"/>
    <xsd:attributeGroup ref="dictRef"/>
    <xsd:attributeGroup ref="value"/>
    <xsd:attributeGroup ref="objectClass"/>
    <xsd:anyAttribute namespace="##other" processContents="lax"/>
  </xsd:complexType>
</xsd:element>

Sample