This is not the final website. It is a demo of the real tool working, made for Y Combinator.
AxisRemedy

31-018 A non-symbolic TrueType font is used for rendering, but for at least one glyph to be rendered the glyph cannot be looked up by any of the non-symbolic cmap entries in the embedded font program.

A glyph cannot be found through any non-symbolic cmap entry.

Checkpoint
31: Fonts
ISO 14289-1 (PDF/UA-1) clause
7.21.6-2
Test type in the protocol
Machine-testable
Applies to
A single object

How AxisRemedy handles it

Tested by the app. AxisRemedy tests this condition itself. For each document it records passed, failed or not applicable, and for every failure the object and the page.

What the check covers

Decided for embedded non-symbolic simple TrueType fonts whose program has a (3,1) cmap and whose encoding is MacRoman or WinAnsi (with /Differences): each code the pages show is taken through its glyph name and Unicode value to the cmap. Names without a single Unicode value and fonts with only a (1,0) cmap are not judged.