MusicXML 4.1 Draft
MusicXML 4.1 Draft > MusicXML Reference > Examples > <group-time>

<group-time>

group-time-element

<part-group number="1" type="start">
   <group-symbol default-x="-10">square</group-symbol>
   <group-barline>yes</group-barline>
   <group-time/>
</part-group>