<div dir="ltr"><div dir="ltr"><div dir="ltr"><div dir="ltr"><div> Marcus,</div><div><br></div><div>Taking your pseudo annotated instances another step..</div><div>Here, instead of a new "meas" model, I made a second "coords" model changing the Position element.</div><div>I want to use this (ra,dec) pair in my Dataset Metadata annotation as the Target.position... the pair is annotated against 2 different coords models.</div><div>Which do I reference in my Target annotation? Or, how would you want to see that?</div><div><br></div><div dir="ltr"> <FIELD ID="RA" name="ra"/><br> <FIELD ID="DEC" name="dec"/><br><br> <INSTANCE type="coords:Position"><br>  <ATTRIBUTE role="ref_frame" value="ICRS"/><br>  <ATTRIBUTE role="latitude" ref="DEC"/><br>  <ATTRIBUTE role="longitude" ref="RA"/><br> </INSTANCE><br><br> <INSTANCE type="coords2:EquatorialPosition"><br>  <ATTRIBUTE role="ref_frame" value="ICRS"/><br>  <ATTRIBUTE role="dec" ref="DEC"/><br>  <ATTRIBUTE role="ra" ref="RA"/><br> </INSTANCE><br><div dir="ltr"><br> <INSTANCE type="ds:Target"><br>  <ATTRIBUTE role="position" ref="???" /><br>  <ATTRIBUTE role="objectClass" value="Star"/><br> </INSTANCE></div><div dir="ltr"><br></div><div>Mark</div><div><br></div><div dir="ltr"><br></div></div></div></div></div></div>