In section [5.2. Absolute lengths: the cm, mm, q, in, pt, pc, px units](https://drafts.csswg.org/css-values-3/#absolute-lengths) the table entry has a capitalized 'Q' unlike every other mention of 'q' unit. Example source can be seen [here](https://github.com/w3c/csswg-drafts/blob/master/css-values/Overview.bs#L1160)