Index: trunk/src/flag.c
===================================================================
--- trunk/src/flag.c	(revision 21749)
+++ trunk/src/flag.c	(revision 21750)
@@ -26,6 +26,7 @@
  *
  */
 
+#include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include "config.h"
@@ -85,3 +86,32 @@
 
 	return (memcmp(f1->t, &f2->t, sizeof(f1->t)) == 0);
 }
+
+const char *pcb_dynflag_cookie[PCB_DYNFLAG_BLEN];
+
+pcb_dynf_t pcb_dynflag_alloc(const char *cookie)
+{
+	pcb_dynf_t n;
+	for(n = 0; n < PCB_DYNFLAG_BLEN; n++) {
+		if (pcb_dynflag_cookie[n] == NULL) {
+			pcb_dynflag_cookie[n] = cookie;
+			return n;
+		}
+	}
+	return PCB_DYNF_INVALID;
+}
+
+void pcb_dynflag_free(pcb_dynf_t dynf)
+{
+	if ((dynf >= 0) && (dynf < PCB_DYNFLAG_BLEN))
+		pcb_dynflag_cookie[dynf] = NULL;
+}
+
+
+void pcb_dynflag_uninit(void)
+{
+	pcb_dynf_t n;
+	for(n = 0; n < PCB_DYNFLAG_BLEN; n++)
+		if (pcb_dynflag_cookie[n] != NULL)
+			fprintf(stderr, "pcb-rnd: Internal error: dynamic flag %d (%s) not unregistered\n", n, pcb_dynflag_cookie[n]);
+}
Index: trunk/src/flag.h
===================================================================
--- trunk/src/flag.h	(revision 21749)
+++ trunk/src/flag.h	(revision 21750)
@@ -40,8 +40,13 @@
 	pcb_unknown_flag_t *next;
 };
 
+#define PCB_DYNFLAG_WORD unsigned long
+#define PCB_DYNFLAG_WLEN ((PCB_DYNFLAG_BLEN-1) / sizeof(PCB_DYNFLAG_WORD)+1)
+typedef PCB_DYNFLAG_WORD pcb_dynflag_t[PCB_DYNFLAG_WLEN];
+
 typedef struct {
-	unsigned long f;                           /* generic flags */
+	unsigned long f;                           /* generic statically assigned flag bits */
+	pcb_dynflag_t df;                          /* dynamically allocated flag bits */
 	unsigned char t[(PCB_MAX_LAYER + 1) / 2];  /* thermals */
 	unsigned char q;                           /* square geometry flag - need to keep only for .pcb compatibility */
 	pcb_unknown_flag_t *unknowns;
@@ -155,6 +160,7 @@
 	} \
 } while(0)
 
+/* Ignores dynamic flags and thermals */
 int pcb_flag_eq(pcb_flag_t *f1, pcb_flag_t *f2);
 #define PCB_FLAG_EQ(F1,F2)	pcb_flag_eq(&(F1), &(F2))
 
@@ -175,4 +181,19 @@
 int pcb_mem_any_set(unsigned char *arr, int arr_len);
 #define PCB_FLAG_THERM_TEST_ANY(P)	pcb_mem_any_set((P)->Flags.t, sizeof((P)->Flags.t))
 
+/*** Dynamic flags ***/
+#define PCB_DFLAG_SET(flg, dynf) (flg)->df[(dynf) / sizeof(PCB_DYNFLAG_WORD)] |= (1 << (dynf) % sizeof(PCB_DYNFLAG_WORD))
+#define PCB_DFLAG_CLR(flg, dynf) (flg)->df[(dynf) / sizeof(PCB_DYNFLAG_WORD)] &= ~(1 << (dynf) % sizeof(PCB_DYNFLAG_WORD))
+#define PCB_DFLAG_TEST(flg, dynf, val) (!!((flg)->df[(dynf) / sizeof(PCB_DYNFLAG_WORD)] & (1 << (dynf) % sizeof(PCB_DYNFLAG_WORD))))
+#define PCB_DFLAG_PUT(flg, dynf, val) ((val) ? PCB_DFLAG_SET((flg), (dynf)) : PCB_DFLAG_CLR((flg), (dynf)))
+
+extern const char *pcb_dynflag_cookie[PCB_DYNFLAG_BLEN];
+
+typedef int pcb_dynf_t;
+#define PCB_DYNF_INVALID (-1)
+pcb_dynf_t pcb_dynflag_alloc(const char *cookie);
+void pcb_dynflag_free(pcb_dynf_t dynf);
+
+void pcb_dynflag_uninit(void);
+
 #endif
Index: trunk/src/globalconst.h
===================================================================
--- trunk/src/globalconst.h	(revision 21749)
+++ trunk/src/globalconst.h	(revision 21750)
@@ -66,6 +66,10 @@
 #endif
 #endif
 
+/* number of dynamic flag bits that can be allocated at once; should be n*64 for
+   memory efficiency */
+#define PCB_DYNFLAG_BLEN 64
+
 #define PCB_MAX_LINE_POINT_DISTANCE     0   /* maximum distance when searching line points; same for arc point */
 #define PCB_MAX_POLYGON_POINT_DISTANCE  0   /* maximum distance when searching polygon points */
 #define PCB_MAX_NETLIST_LINE_LENGTH     255 /* maximum line length for netlist files */
Index: trunk/src/main.c
===================================================================
--- trunk/src/main.c	(revision 21749)
+++ trunk/src/main.c	(revision 21750)
@@ -52,6 +52,7 @@
 #include "polygon.h"
 #include "buildin.h"
 #include "build_run.h"
+#include "flag.h"
 #include "flag_str.h"
 #include "plugins.h"
 #include "plug_footprint.h"
@@ -282,6 +283,7 @@
 	pcb_actions_uninit();
 	pcb_uilayer_uninit();
 	pcb_cli_uninit();
+	pcb_dynflag_uninit();
 }
 
 static int arg_match(const char *in, const char *shrt, const char *lng)