we just wrote a code comment we're proud of:

Though this can be counterintuitive to programmers, it is normal for fonts to draw outside their bounds. Font metrics are primarily intended to advise about graphic-design topics, which are socially defined and do not necessarily obey mathematical identities, even when such identities are offered as explanations of their meaning.

Instead, the mathematical meaning of these metrics serves as a first layer, a literal meaning which provides a reference point for additional layers of meaning to be added atop, in the same fashion as how the duration of a musical measure is not actually fixed during a live performance.

There are very good reasons that programmers find this state of affairs deeply saddening, but there is nothing to be done but deal with it.