Specifies whether an attribute is single or multi select. If multi
is specified, valid values must be specified as well. Only used within
attributes.
Create a multi-select attribute
<create server="ramServer">
<attribute>
<name>Affected versions</name>
<select>multi</select>
<validValue>1.0</validValue>
<validValue>1.1</validValue>
<validValue>1.2</validValue>
<validValue>2.0</validValue>
</attribute>
</modify>