Public-Sans: Feature: Consider making d, b, q, p distinct under reflection

[briandeconinck]

Is your feature request related to a problem? Please describe.

Reading Gareth Ford Williams' 2020 blog post on typeface accessibility, Williams proposes "ensure there is no mirroring" as an accessibility guideline:

All sighted young children horizontally flip letters as part of their early neurological development. At around the age of six years old, however, this neurological trait resolves itself as part of ongoing physiological development, however in some children this development stage doesn’t occur and accordingly letter flipping effect is lifelong. In extremely rare occasions the mirroring effect may also be re-introduced because of brain trauma. As such d and b, or q and p, should be obviously unique in shape and have no ambiguous characteristics.

Williams then calls out Public Sans as a typeface in which d, b, q, and p are not sufficiently unique. I've verified that:

• d and b are identical under horizontal reflection
• q and p are identical under horizontal reflection
• q is almost identical to d under vertical reflection
• p is likewise almost identical to d under vertical and horizontal reflection

Image below illustrates these characters under rotation in Public Sans:

Describe the solution you'd like

I'm going to be terrible and open an issue without providing any specific fixes. Hopefully someone with actual typographic design experience is interested in taking this on! But broadly speaking the goal would be to update d, b, q, and p be unique under reflection. I'll note that Williams' blog post provides examples of those letters made more identifiable in a typeface developed while he was at the BBC.

Describe alternatives you've considered

No response

Additional context

This is probably not a high-priority issue, but I'll note that it came up in a conversation about supporting VA.gov users that have experienced traumatic brain injuries. We haven't received any specific feedback that I'm aware of but it would be nice to know we're accounting for a potential barrier.

I'll also note that the Gareth Ford Williams blog post doesn't cite any research, and it may be worth validating this approach before changing the glyphs. A cursory search on Google Scholar seems broadly consistent with what he's suggesting as a guideline but I haven't done any reading deeper than that.

Code of Conduct

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• I checked the current issues for duplicate feature requests.