This declaration for the <objectName> element shows how standard TEI markup could be used within ‘museum’ elements:

 
<!ELEMENT %n.objectName - - (%m.phrase; | #PCDATA)* >
<!ATTLIST %n.objectName %a.global;
                        %a.type;
                        %a.names;   >

while this shows a museum-specific sub-structure for recording a measurement:

 <!ELEMENT %n.measureStruct - - ((%n.object-extent;)?, 
                (%n.num;, (%n.unit;)?)+,
                (%n.qualifier;)?, (%n.date;)?,
                (%m.remarks-citation;)*) >