Or just YYMMDD, since there's typically not all that many things you create in one day, so you can just browse among the search hits and it'll be obvious which of the hits you had in mind.

You're lucky to regard note names as stable enough that they work as unchanging IDs for you!

But is it not then the same thing, because you already "allocated an ID" by naming it? Did you, before coming up with the 4-char hash, often label things outside the vault with the same names as those found in your vault?

Aye, so this is fine as long as there's just one entity generating IDs, so it can automatically check for collision and re-generate.

In a distributed system it's another matter.

I'm currently using 6 base-40 chars (upcase and lowcase letters, so e.g. "SXJwzQY") that represent an integer Unix time.

The base-40 alphabet is enough that all IDs up until year ~2099 will fit in 6 chars, and it's nicer to type on the phone when you only have to switch between two keyboard modes, the upcase and lowcase but not also the numbers and symbols mode.

In the spirit of "analog browsing", there is always https://addons.mozilla.org/en-US/firefox/addon/downthemall

"First Sea Lord" is such a great rank.