I'm currently experimenting with the best position to set anchors in an OpenType font.
Now, when I ask the app Glyphs to place my anchors, it takes the width of the total letter, and set the anchor in the middle of the width.
And it does the same for the punctuation.
But when the punctuation (automatically) is merged on the letter, this default behaviour does not always result in the best combination: some punctuation has to shift to the left, other to the right.
Are there some guidelines for the best placing of the anchors or is it totally up to the taste of the designer? (Read; the designers eye...)
Here is a good place to start:
http://diacritics.typo.cz/index.php?id=1
and
http://en.wikipedia.org/wiki/Caron