<editor role="Researcher">
<persName>
<forename>Toma</forename>
<surname>Tasovac</surname>
</persName>
<affiliation n="1">DARIAH-EU, Digital Research Infrastructure for the Arts and
Humanities</affiliation>
<affiliation n="2">BCDH, Belgrade Center for Digital Humanities</affiliation>
</editor>
<editor role="Developer">
<persName>
<forename>Boris</forename>
<surname>Lehečka</surname>
</persName>
<state>Freelancer developer</state>
</editor>
I'd rather not introduce an additional element for that. You can either use affiliation and put Freelance developer there, or simply have no affiliation...
@ttasovac I need to include the collaboration of @daliboris in the header. In his case, he is a freelancer with no affiliation. I'm using
state
(not allowed). https://tei-c.org/release/doc/tei-p5-doc/en/html/ref-editor.html