<html aria-label="message body"><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><br id="lineBreakAtBeginningOfMessage"><div><br><blockquote type="cite"><div>On 16 Feb 2026, at 14:55, Gerard Lemson via dm <dm@ivoa.net> wrote:</div><br class="Apple-interchange-newline"><div><span style="caret-color: rgb(0, 0, 0); font-family: Monaco; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration: none; float: none; display: inline !important;">How the value should be expressed is I in my opinion a question of the serialization format. One thing to realize is that VO-DML is not so much about serialization as about annotation. If one annotates some serialization element (say a column in VOTable) as storing an attribute with a <<semanticconcept>> the serialization could mandate that that a URI identifying the concept should be written, but I think for a standard like VOTable one might allow the usual UCDs?</span><br style="caret-color: rgb(0, 0, 0); font-family: Monaco; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: 400; letter-spacing: normal; orphans: 2; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-stroke-width: 0px; text-decoration-line: none; text-decoration-thickness: auto; text-decoration-style: solid;"></div></blockquote></div><br><div><br></div><div>This might be at the core of why different people have slightly different views on what VO-DML can/should do - I personally am wanting to do direct serialization of my model instances into XML/JSON/RDB, so I want the ability to “tighten-up” the serialization within the VO-DML metamodel itself, rather than defer some of these decisions to another serialization format - I cannot see any reason why this “direct” serialization use need conflict with the “annotation” serialization usages. We could probably say explicitly that the “annotation” style usages (such as MIVOT) can “override” the direct serialization rules in the cases where there is a conflict.</div></body></html>