The metadata librarians are grouping the genre values into categories and subcategories, and will be supplying us with a spreadsheet that lists the genre values in the first column, the narrowest subcategory to which it applies in the second column, the next broader subcategory in the third column, and so forth. The spreadsheet may have as many as 5 or 6 columns, with the broadest categories in the far right column.
These will be encoded as described in the The faceting schema, as recursive genre_f (genre faceting) values, and added into the MODS extension field.
For example, if the spreadsheet contains:
beagle dog canine mammal animal
Then the facet encoding will be:
<genre_f>animal <genre_f>mammal <genre_f>canine <genre_f>dog <genre_f>beagle</genre_f> </genre_f> </genre_f> </genre_f> </genre_f>
The script for this is under development in /srv/scripts/metadata/faceting/genres, and will then be incorporated into the acumenFacets library and production scripts.