I'm assuming it boils down to judgment calls, but I'm wondering about generally acceptable changes that can be made between font version updates.
It seems clear that obvious glitches should be fixed, like a mysterious control point that somehow ended up a ways away from where it should be. I'm also assuming that additions to the font would be fine, like adding a lesser-used Cyrillic character or a locl variant at a customer's request.
What I'm much less certain about are aesthetic changes. How about adjusting the curve in a zeta because it doesn't look quite right or making a slash a little thinner or thicker? Or even something more substantial, like altering a glyph in a way that affects its width metrics or going so far as changing the look of an ampersand?
As a graphic designer and user of type myself, I'd obviously be fine with bug fixes and additions, but if, say, a slightly widened O in a new version of a font caused a series of cascading line shifts in a magazine layout I was working on, I'd be less than pleased with the change.
Anyway, does anyone have any general guidelines or thoughts on this? I have a font family with around 6,000 glyphs that I'm close to finishing up, and I swear that as soon as I upload it to the distributors, I'll see an endless string of adjustments that I wish I would have made. At what point do you call it good enough, and what kind of flexibility is generally acceptable for making fixes, tweaks and changes between versions?