<OME xmlns="http://www.openmicroscopy.org/Schemas/OME/2015-01"
...
<AnnotationRef ID="Annotation:1"/>
</Image>
<MapAnnotation ID="Annotation:1">
<Description>Additional metadata description</Description>
<Value>
<M K="Key-1">Value-1</M>
<M K="Key-2">Value-2</M>
</Value>
</MapAnnotation>
</StructuredAnnotations>
</OME>
See the OME-XML sample
Drop from model,
<Folder ID="Folder:1" Name="CMPO"> <FolderRef ID="Folder:2"/> <FolderRef ID="Folder:7"/> </Folder> <Folder ID="Folder:7" Name="Cell Component"> <FolderRef ID="Folder:8"/> <ROIRef ID="Roi:14"/> </Folder>