Hi!. I needed a form to add contributor.author from a drop-down list but also to have the option to write the author's name in case it is not in the list. So I defined the following fields:
<row>
<field>
<dc-schema>dc</dc-schema>
<dc-element>contributor</dc-element>
<dc-qualifier>author</dc-qualifier> <repeatable>true</repeatable>
<label>Autor</label>
<style>col-sm-4</style>
<input-type value-pairs-name="autores">dropdown</input-type> <hint>Nombre del autor.</hint>
<required>Obligatorio</required>
</field>
<field>
<dc-schema>dc</dc-schema>
<dc-element>contributor</dc-element>
<dc-qualifier>author</dc-qualifier> <repeatable>true</repeatable>
<label>Autor</label>
<style>col-sm-4</style>
<input-type>onebox</input-type> <hint>Nombre del autor.</hint>
<required></required>
</field>
</row>
Everything is OK if I set values for only one of those fields. If I set values for both, the result is that the record only has the values from the onebox field as you can see in the images.

Thanks for any help!
Diego