Marking experimental features into the GUI (user interface)
Quote from release notes of 1.1.1.27:
CardDAV support for Fruux and Memotoo service providers (experimental)
Still, Settings > Accounts > (pulley menu) Add account shows these as they were ready, similar to any other account. I'd like to see them (and any other experimental features) marked with some special sign/text while they are still experimental or in beta stage in development.