id 

The value of attribute id in category entry identifies the data block.
 
Note that this item need not be a number; it can be any unique
identifier.

Attribute Information

Used By

Element PDBx:entryType/PDBx:entry

Source 

<xsd:attribute name="id" use="required" type="xsd:string">
  <xsd:annotation>
    <xsd:documentation xml:lang="en">The value of attribute id in category entry identifies the data block. Note that this item need not be a number; it can be any unique identifier.</xsd:documentation>
  </xsd:annotation>
</xsd:attribute>

Sample