* create a authority category called "EDITORS"
* set :
200$a => ISBN
200$b => editor
200$c => (repeatable) collection.
Then enter, for example :
$a 23
$b Hachette Litterature
$c collection1|collection2|collection3
map your "editor" field to plugin 210c, your "collection" field to plugin 225a
Once you arrive on the editor field, if the beginning of the ISBN exists, the editor is automatically found.
Once you arrive on collection field, click on ... you can choose in the collection list.
The 210c / 225a comes from the UNIMARC editor/collection field, but should work as well with MARC21.
