Information hoarding anti pattern

In The Phoenix Project the author describes an interesting antipattern: Brent is a super-important dev-ops engineer that personally knows the details of every new and old implementation and setup, but he does not share, document or distribute his knowledge. Ultimately every small task or large project crucially depends on him.

While this Brent is hailed as a hero by the whole organization, the main protagonist of the book recognized that this is an anti-pattern and starts to break down this information “person-silo” by shadowing him and documenting his knowledge.

Is there a name for this antipattern? Is it widely recognized?

How can I know (without going to the station) if RTAP is offering the Anti Pollution tickets?

The Paris public transit system (RTAP) offers a reduced fare on days of high pollution, as described here: (Google Translated).

This fare is a very good deal, especially as a tourist!

It has been offered so far every day that I have been visiting, but I only know that because I have been to the train station and seen it advertised. Is there a website where I can look to see whether a particular day is an anti pollution day?