where is q3map2 filter?

~/dev/netradiant/tools/quake3/q3map2 $ grep -R -- 'filter' . | sed -e 's#/\*[^/\*]*\*/##'| grep filter | grep -v '[a-zA-Z]filter\|filter[a-zA-Z]'
./changelog.q3map1:									most wierd edge cases with filter
./changelog.q3map1:									NVIDIA's website for Photoshop filter
./q3map2.h:Q_EXTERN qboolean filter Q_ASSIGN( qfalse );
./nav.cpp:	//dont filter ledge spans since characters CAN walk on ledges due to using a bbox for movement collision
./help.c:		{"-extrawide", "Deprecated alias for `-super 2 -filter`"},
./light_ydnar.c:	   filter pass
./light_ydnar.c:				if ( deluxemap && lightmapNum == 0 && ( *cluster < 0 || filter ) ) {
./changelog.q3map2.txt:  Also operates on individual lightsources, so per-lightsource filter/kernel
./light.c:		else if ( !strcmp( argv[ i ], "-filter" ) ) {
./light.c:			filter = qtrue;
./light.c:			filter = qtrue;
./light.c:			Sys_Printf( "The -extrawide argument is deprecated, use \"-filter [-super 2]\" instead\n" );