onum — Oldstyle Figures
onum (Oldstyle Figures) replaces figures from their default or lining form with oldstyle forms.
Oldstyle figures blend into the flow of running text set in upper- and lowercase, so this feature suits body copy. Characters designed for use with figures may also have oldstyle versions, and can be included as well.
The counterpart in the figure-style axis is lnum (Lining Figures). The specification states that onum overrides the results of lnum. The figure-width axis (pnum and tnum) is independent of this, and the two axes are combined in use. zero applies only to the lining form of the zero, so it has no effect on the oldstyle zero that onum produces.
Example
Section titled “Example”Vollkorn’s default figures are already oldstyle and proportional, so applying onum produces no visible change. This example uses EB Garamond, whose default figures are lining.
.fea source
Writing it in a feature file
Section titled “Writing it in a feature file”The rules are written with Lookup Type 1.