This proposal would add a "Prose" work type.

http://en.wikipedia.org/wiki/Prose

The "Prose" work type would be beneficial for audiobook releases, which are required to link to a work for each book being read:

https://wiki.musicbrainz.org/Style/Specific_types_of_releases/Audiobook

Some examples of places where a "Prose" type would be used:

http://musicbrainz.org/work/aeae405d-f55d-43f0-b6b2-8611df82f3b1
http://musicbrainz.org/work/f76307a4-179e-47aa-a843-de31e40202bf
http://musicbrainz.org/work/68a1472d-0ba1-45fd-9ddc-4f51c42dfd0e
http://musicbrainz.org/work/ccefd76a-b870-4ed0-aa04-d391c8e98cb6
http://musicbrainz.org/work/30922499-9825-4ffa-a102-fb711f553c04