A list of Footprint sflag values, with their effects as these become known. Some flags should only be used with particular element types; these are shown in italics when they apply.
The file strflags.c in the PCB source contains this code, which might be a complete list of sflag settings:
static FlagBitsType object_flagbits[] = {
{ PINFLAG, N ("pin"), ALL_TYPES },
{ VIAFLAG, N ("via"), ALL_TYPES },
{ FOUNDFLAG, N ("found"), ALL_TYPES },
{ HOLEFLAG, N ("hole"), PIN_TYPES },
{ RATFLAG, N ("rat"), RATLINE_TYPE },
{ PININPOLYFLAG, N ("pininpoly"), PIN_TYPES | PAD_TYPE },
{ CLEARPOLYFLAG, N ("clearpoly"), POLYGON_TYPE },
{ HIDENAMEFLAG, N ("hidename"), ELEMENT_TYPE },
{ DISPLAYNAMEFLAG, N ("showname"), ELEMENT_TYPE },
{ CLEARLINEFLAG, N ("clearline"), LINE_TYPE | ARC_TYPE | TEXT_TYPE },
{ SELECTEDFLAG, N ("selected"), ALL_TYPES },
{ ONSOLDERFLAG, N ("onsolder"), ELEMENT_TYPE | PAD_TYPE | TEXT_TYPE },
{ AUTOFLAG, N ("auto"), ALL_TYPES },
{ SQUAREFLAG, N ("square"), PIN_TYPES | PAD_TYPE },
{ RUBBERENDFLAG, N ("rubberend"), LINE_TYPE | ARC_TYPE },
{ WARNFLAG, N ("warn"), PIN_TYPES | PAD_TYPE },
{ USETHERMALFLAG, N ("usetherm"), PIN_TYPES | LINE_TYPE | ARC_TYPE },
{ OCTAGONFLAG, N ("octagon"), PIN_TYPES | PAD_TYPE },
{ DRCFLAG, N ("drc"), ALL_TYPES },
{ LOCKFLAG, N ("lock"), ALL_TYPES },
{ EDGE2FLAG, N ("edge2"), ALL_TYPES },
{ FULLPOLYFLAG, N ("fullpoly"), POLYGON_TYPE},
{ NOPASTEFLAG, N ("nopaste"), PAD_TYPE }
};