pattern 

May point to the pattern on which an activity or collaboration is
based. This attribute is used only when not using the concrete BT
patterns provided.

Attribute Information

Used By

Complex Type BusinessCollaborationType

Source 

<xsd:attribute name="pattern" type="xsd:anyURI">
  <xsd:annotation>
    <xsd:documentation>May point to the pattern on which an activity or collaboration is based. This attribute is used only when not using the concrete BT patterns provided.</xsd:documentation>
  </xsd:annotation>
</xsd:attribute>

Sample