A <bom> element defines information to be logged to the Bill of Materials (BOM) for the job; it should be enclosed in a <match> element. A <bom> element must specify a category and section within the BOM and defines which numbered variables ($1...$n) collected by the <match> element should be converted to fields for the BOM data.
<bom category="Source" section="changesets" >
<field name="Change" text="$1"/>
<field name="Date" text="$2"/>
<field name="User" text="$4"/>
</bom>
Use the condition="function" attribute to control whether the <bom> element is written to the BOM report. The value of function is an expression that evaluates to true or false. If the expression evaluates to true, the information in the <bom> element is written to the BOM; otherwise, it is not written. See Condition functions.