After finding The Causal Optimist blog and seeing a post on book covers, this one reminded me of my own neighbourhood form/sign, and that I was going to dig out some favourites in what is essentially a design pattern of public notices being played for laughs.

A recent well done version of the tear-off-tab gag is from the wonderfully absurd Pablo Rochat (video on Instagram):

The first version of the tear-off-tab that I remember being used for fun was a very simple sign that offered little tabs of ‘hope’ to be torn off. Annoyingly though I can’t find it. It must have been from the early 2000s, but finding it again in this haystack of copycats/remixes is sadly impossible.
Excitedly though, I was able to track down this utter classic:

No tear-off, but in my opinion, still the best ever play on the DIY public notice format. Format, pattern, system, trope? Oh, how these words overlap in annoying ways.
