Numbers with varying heights, ascenders, and descenders (like lowercase letters).

https://en.wikipedia.org/wiki/Text_figures

I presume numbers with the top aligned with the x-height[0]. Corbel and Candara both have them if you look at the screenshots on the GH page[1].

[0] https://en.wikipedia.org/wiki/X-height

[1] https://github.com/system-fonts/modern-font-stacks#classical...