According to @franklin-feingold, this issue was brought up in a recent steering group meeting:

Intro

We are rendering the specification in several flavors, such as:

• stable ... the currently accepted version of the spec
• latest ... distinguished by a -dev appendix to the version of the spec in the header of the rendered spec. This version is not currently released/accepted, but it will become stable eventually.
• and previous versions
  • v1.2.0
  • ...

Problem

However, we are also rendering some development branches, such as the one for derivatives. Currently, this development branch "looks" similar to the "stable" rendered spec. This is a problem, because users may accidentally use this version of the specification for formatting datasets, although this is merely a development branch and subject to change.

Solution

A potential solution would be to add a watermark or similar sign to all renderings that are not either

• stable
• latest
• or previously released (outdated) version

What I have looked into so far

• potentially adding a "ribbon" to the page using html similar to the "form me on github" ribbons
  • --> turns out to be difficult with MkDocs, because we would want the ribbon only on specific versions of the specification
• Adding a watermark of some kind on top of our source during the rending process
  • --> I didn't find any READTHEDOCS options that support this

This leaves me with the only feasible option at this point: For every rendered development version (currently only derivatives), we can edit this line in the sourcecode:

---site_name: Brain Imaging Data Structure v1.3.0-dev
+++site_name: Brain Imaging Data Structure v1.3.0-DERIVATIVES_DRAFT

Opinions and alternatives are welcome, I am not super happy with this solution.