I'm trying to figure out all the values for the fields of FT_Outline. One of those fields in a flag with size of char, in the documentation it states:
If bit 2 is set, bits 5-7 contain the drop-out mode (as defined in the OpenType specification; the value is the same as the argument to the ‘SCANMODE’ instruction).
But I cannot find where these values are actually defined. I see drop out control mode in opentype, but the number of bits requires to store that is way more than 3, and I've found no mention of this "SCANMODE" instruction, google turns up nothing.