The font metrics are different for most any font (and/or font family). How they are calculated in various applications is a separate issue. As far as I remember (and hey, I am getting older...), Adobe applications do not retrieve the metrics from the respective OS and instead calculate metrics apart from the OS--at least ID does for optical kerning. In general, the bowls will rise above the x-height and cap height and below the baseline. But this depends on the font author for their particular font. Some caps without a bowl will rise above the cap height, etc., etc. As far as placing guidelines for these metrics, just be consistent. Here's a cap T. You can see the various heights. The top corners sit 7 f-units above the cap height meteric... And if I were to take a screen shot of the baseline, you would see it sits 2 f-units below the baseline. A screen shot of the lowercase c shows it both rising above the x-height and below the baseline. Different fonts will be placed at various positions.
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