Solo projects are currently classified as persons in MusicBrainz, and therefore follow Style for persons such as using a date of birth as their start date. This doesn't make sense in the majority of "project" cases, where a project has a start date that is a long time after the person's date of birth. A new artist type "project" could sit between "person" and "group" and allow for more logical guidelines that don't fully match either.  This would also help reiterate that https://musicbrainz.org/doc/Style/Artist#Performance_names_and_legal_names exists.

Examples of projects that are currently classified as persons:

1. https://beta.musicbrainz.org/artist/cb191900-8ad8-46b9-b021-a093ee2b2f9b - officially, this should have a start date of 2014, not 1980.
2. https://beta.musicbrainz.org/artist/741a8da6-9b87-4b49-acda-6cc6d9f579ac