Correct me if I’m wrong, but isn’t optical kerning a fallback option for fonts that have no special kerning rules? When would you use it over the font designer’s hand-specified kerning?

Not necessarily.

See my other comment here about kerning depending on font size.

A font may be kerned to be typeset at 10–16pt but you use it for headlines at 24p. The optical kerning may be better suited then.

The game is for a different purpose. Once you can get by eye the "book" kerning you can start breaking the rules.

Is there such thing as book kerning? My impression is that it's an artistic decision.

All my knowledge of keming came from roundabout sources, but I think there are some pretty serous sources. I've never gotten around to https://en.wikipedia.org/wiki/Computers_and_Typesetting but that's a pretty serious start.

There's the normal stuff about rivers and lakes, but from the game Toronto is a kinda funny one, To ronto, what's ronto? why are you going there? I think there's a good amount of looking for potential mis-parses, and making sure the reader never slips out of reading, and is forced to re parse.

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Damn you.