Original idea as outlined by @erquhart

Idea:

Allow for a 'Singles' content type, designed for one-off, often publicly-published pages such as 'About', 'Contact', etc. Anything that would not be appropriate as a repeatable object template in the way that 'folder' type Collections work in the CMS today.

This allows for the distinction in the 'Content' interface of these different content types. Collections allow for (+) buttons, Singles do not, as they are one-off. This is largely represented in the 'file' Collection type available in the CMS today.