• Applies to: TTF
• Fontspector can hotfix?: no
• Fontspector can fix sources?: no

Hinted fonts must have head table flag bit 3 set.

Per https://docs.microsoft.com/en-us/typography/opentype/spec/head, bit 3 of Head::flags decides whether PPEM should be rounded. This bit should always be set for hinted fonts.

Note: Bit 3 = Force ppem to integer values for all internal scaler math; May use fractional ppem sizes if this bit is clear;

• https://github.com/fonttools/fontbakery/issues/2338

• universal (in section 'Universal Profile Checks')

• googlefonts (in section 'Universal Profile Checks')