Quote from the fvar documentation in OpenType spec v1.9 (my emphasis):
The subfamilyNameID field provides a name ID that can be used to obtain strings from the 'name' table that can be treated as equivalent to name ID 17 (typographic subfamily) strings for the given instance. Values of 2 or 17 can be used; otherwise, values must be greater than 255 and less than 32768.
I hereby propose a new fvar check that validates that the value of subfamilyNameID used by each InstanceRecord be 2, 17, or greater than 255 and less than 32768.
The check should FAIL if the conditions are not met.
Quote from the
fvardocumentation in OpenType spec v1.9 (my emphasis):I hereby propose a new
fvarcheck that validates that the value of subfamilyNameID used by each InstanceRecord be 2, 17, or greater than 255 and less than 32768.The check should FAIL if the conditions are not met.