This is why, besides kerning every possible letter combination in all of my fonts, I also kern hyphens, commas, periods, colons, semicolons and curly and non-curly single and double quotes...

If setting in Arno, I'd probably just do this:

Find/Change>
Find what: Q,
Change to: Q^3,
Case sensitive - on

For my recent Williams Caslon, Font Bureau folks talked me into having my short tailed Q default,(IRAQ) and putting in the first stylistic an instruction to substitute Qu with the traditional long-tailed Q. There is also a stylistic set that substitutes in all the historical style characters, so the long-tailed Q is everywhere then.

William: What I've been doing in my font (whose J, j, f, y tend to create collisions), is maintaing a list of letters that cause collisions (have descenders on the right side, in the case of J and Y, or spaces, since they just looked weird). That way, whenever possible, the longer preferred form is used, but automatically switches to a shortened form as necessary. Basically like what you've had to do with the Q+u, but doing it with Q+[abcedfhiklmnoqrstuvwxz]. You can have either one be the default in that case.

Related: contextual alternates for f + umlauts.

Ivan, adding a third space is probably a bad idea, if the InDesign files you're creating will be used for any other purpose, as they would in bookwork -- unless you know for sure that the result isn't the insertion of any Unicode *character*, such as the 3-to-em space. You need to export everything InDesign will let you & check to see what's there. On the other hand, we know a kern won't show up as a character, but AFAIK, you can't insert a kern with the InDesign Find/Replace tool.

The problem Q with the long tail mentioned above is the standard Q in Arno. There is an optional Q. It has a longer tail.

What is (to me) a problem flag with any glyph is where it needs to be kerned to a following glyph using a kern value approaching or exceeding a wordspace. This may not give rise to any visual nightmares (be a problem) in some cases, but often is in others. That's when a solution is needed. Redraw the glyph, create an alternate with an accompanying feature that will automatically resolve the problem, something like that.

AFAIK, you can't insert a kern with the InDesign Find/Replace tool.

Charles, you can use InDesign’s GREP search, and the ‘positive lookahead’ feature.
1. Create a character style that sets the needed kern.
2. Search for Q(?=,) – a ‘Q’, only if followed by a comma.
3. Replace with your style.

Since CS4, you can make this even shorter and use a GREP style that automatically searches for this pattern and applies the desired formatting on the fly.

I know this is not the same as ‘inserting a kern’, and you probably were already aware of this functionality.
Florian

Florian, yes, that would work. Some people, on export, do include character styles, so you might be setting up a *situation* later. Not a big deal. You can insert a kern through scripting too. Just not through the Find/replace pulldown pallet.