The “strange line” is a timeline string like this that I put underneath my mails as a signature for the different phases of my (partial) retirement:
2025-04-04: RED .................................................. 674
Since 2023-06-01, I am retired (RED).
The timeline is created by a small Haskell program that you may also execute by yourself by clicking the following links:
Exactly. In case of interest, you find the source code of the timeline program including additional hints here.
The former e-mail signature is archived here.
Wu