diff --git a/VERSION b/VERSION
index b6eeaf68..de3ac290 100644
--- a/VERSION
+++ b/VERSION
@@ -1 +1 @@
-8.3.516
+8.3.517
diff --git a/cif/CIFgen.c b/cif/CIFgen.c
index 9315e36e..67950ba1 100644
--- a/cif/CIFgen.c
+++ b/cif/CIFgen.c
@@ -4664,8 +4664,8 @@ cifBridgeLimFunc2(
  * cifInteractingRegions --
  *
  *	Process each disjoint region and copy the entire content of each
- *	region for which any part of the region overlaps with <...>
- * 	to the current CIF plane.
+ *	region for which any part of the region overlaps with co_cifMask
+ *	or co_paintMask to the current CIF plane.
  *
  * Results:
  *	None.
@@ -4714,6 +4714,19 @@ cifInteractingRegions(
 	    /* Get tile area for interaction search */
 	    TiToRect(t, &area);
 
+	    /* "interacting" includes touching as well as overlapping, so expand
+	     * search by one unit in every direction and then check overlap.
+	     * NOTE:  This catches catecorner-touching material, which is
+	     * assumed not to be an issue.
+	     */
+	    if ((pointertype)op->co_client & CIFOP_INT_TOUCHING)
+	    {
+		area.r_xbot -= 1;
+		area.r_xtop += 1;
+		area.r_ybot -= 1;
+		area.r_ytop += 1;
+	    }
+
 	    /* Check if this tile interacts with the rule's types, or skip	*/
 	    /* if already known to be interacting.				*/
 
@@ -4752,11 +4765,12 @@ cifInteractingRegions(
 		}
 	}
 
-	/* op->co_client is an invert bit indicating the rule is "not-interact",
-	 * so invert the sense of "interacts".  Then the non-interacting regions
-	 * will be kept and the interacting regions will be discarded.
+	/* op->co_client has an invert bit indicating the rule is "not interacting"
+	 * or "not-overlapping", so invert the sense of "interacts".  Then the non-
+	 * interacting/overlapping regions will be kept and the interacting/
+	 * overlapping regions will be discarded.
 	 */
-	if (op->co_client == (ClientData)1)
+	if ((pointertype)op->co_client & CIFOP_INT_NOT)
 	    interacts = (interacts) ? FALSE : TRUE;
 
 	/* Clear the tiles that were processed in this set, first copying them	*/
diff --git a/cif/CIFint.h b/cif/CIFint.h
index 18316843..6bd6b983 100644
--- a/cif/CIFint.h
+++ b/cif/CIFint.h
@@ -171,6 +171,9 @@ typedef struct cifop
 #define CIFOP_BRIDGELIM 23
 #define CIFOP_MASKHINTS 24
 
+/* Definitions of bit fields used in the value of co_client for CIFOP_INTERACT */
+#define CIFOP_INT_NOT	   0x1		/* Inverted sense (not interacting) */
+#define CIFOP_INT_TOUCHING 0x2		/* Include both touching and overlapping */
 
 /* Added by Tim 10/21/2004 */
 /* The following structure is used to pass information on how to draw
diff --git a/cif/CIFtech.c b/cif/CIFtech.c
index 7d4a5360..d9053ad4 100644
--- a/cif/CIFtech.c
+++ b/cif/CIFtech.c
@@ -1095,12 +1095,22 @@ CIFTechLine(
 	newOp->co_opcode = CIFOP_BRIDGE;
     else if (strcmp(argv[0], "bridge-lim") == 0)
 	newOp->co_opcode = CIFOP_BRIDGELIM;
-    else if (strcmp(argv[0], "interact") == 0)
+    else if (strcmp(argv[0], "overlapping") == 0)
 	newOp->co_opcode = CIFOP_INTERACT;
-    else if (strcmp(argv[0], "not-interact") == 0)
+    else if (strcmp(argv[0], "nonoverlapping") == 0)
     {
 	newOp->co_opcode = CIFOP_INTERACT;
-	newOp->co_client = (ClientData)1;
+	newOp->co_client = (ClientData)CIFOP_INT_NOT;
+    }
+    else if (strcmp(argv[0], "interacting") == 0)
+    {
+	newOp->co_opcode = CIFOP_INTERACT;
+	newOp->co_client = (ClientData)CIFOP_INT_TOUCHING;
+    }
+    else if (strcmp(argv[0], "noninteracting") == 0)
+    {
+	newOp->co_opcode = CIFOP_INTERACT;
+	newOp->co_client = (ClientData)(CIFOP_INT_TOUCHING | CIFOP_INT_NOT);
     }
     else
     {
@@ -2463,6 +2473,7 @@ CIFTechOutputScale(
 			case CIFOP_MASKHINTS:
 			case CIFOP_MAXRECT:
 			case CIFOP_NET:
+			case CIFOP_INTERACT:
 			    break;
 			case CIFOP_BRIDGELIM:
 			case CIFOP_BRIDGE: