Font downloads must be disallowed (Restricted Sites zone).
It is possible that a font could include malformed data that would cause Internet Explorer to crash when it attempts to load and render the font. Downloads of fonts can sometimes contain malicious code. Files should not be downloaded from restricted sites. This policy setting allows you to manage whether pages of the zone may download HTML fonts.
How this relates to the STIG checklist: STIG vs SCAP benchmark.