I think this is also a kind of tagging.
"Now pick another random black dot to start from and color it white too. From this black dot" from which black dot, the white one?
"single step in a random direction, coloring the new dot white and drawing a line between the two dots". How big of a step is we need to draw a line? Ok, so where not talking about pixels, and where drawing black and white dots on a background of... let's imagine grey?
"backtrack along your path until you’re back at the dot that you were trying to color white" does this algorithm ever terminate in any tractible time?
ISO 8601 allows for 2 or 6 digit years. Truncating to 2 is just incorrect, and 6 digits is absurd. And you can read the RFC without paying ISO - and you can discuss the RFC with people who have also read it instead of relying on people using the Wikipedia page to interpret and explain ISO 8601.
I have a scheduling service at work and I keep getting requests for implementing ISO 8601 timestamps but I ignore them. RFC3339 is the way forward.
Totally insufficient for capturing important future events like the dead of the sun.