diff --git a/commands/CmdLQ.c b/commands/CmdLQ.c
index f815f6c5..a67bd2ed 100644
--- a/commands/CmdLQ.c
+++ b/commands/CmdLQ.c
@@ -2296,6 +2296,8 @@ parsepositions:
     editDef->cd_flags |= (CDMODIFIED | CDGETNEWSTAMP);
 }
 
+#define PROPERTY_TYPE_COMPAT	4	/* Last entry in cmdPropertyType */
+
 /*
  * ----------------------------------------------------------------------------
  *
@@ -2335,9 +2337,11 @@ CmdDoProperty(
 
     int printPropertiesFunc();		/* Forward declaration */
 
-    /* These should match the property codes in database.h.in */
+    /* These should match the property codes in database.h.in, except
+     * for "compat" which must come at the end.
+     */
     static const char * const cmdPropertyType[] = {
-	"string", "integer", "dimension", "double", NULL
+	"string", "integer", "dimension", "double", "compat", NULL
     };
 
     /* If a property type is given, parse it and then strip it from
@@ -2348,8 +2352,11 @@ CmdDoProperty(
 	proptype = Lookup(cmd->tx_argv[argstart], cmdPropertyType);
 	if (proptype >= 0)
 	{
-	    locargc--;
-	    argstart++;
+	    if (proptype != PROPERTY_TYPE_COMPAT)
+	    {
+		locargc--;
+		argstart++;
+	    }
 	}
 	else
 	    proptype = PROPERTY_TYPE_STRING;	/* default */
@@ -2373,6 +2380,19 @@ CmdDoProperty(
 
     else if (locargc == 2)
     {
+	/* If the property type was "compat", then give the state of the
+	 * compatibility flag and return.
+	 */
+	if (proptype == PROPERTY_TYPE_COMPAT)
+	{
+#ifdef MAGIC_WRAPPER
+	    Tcl_SetObjResult(magicinterp, Tcl_NewBooleanObj(DBPropCompat));
+#else
+	    TxPrintf("%s\n", (DBPropCompat == TRUE) ? "True" : "False");
+#endif
+	    return;
+	}
+
 	/* print the value of the indicated property */
 	proprec = (PropertyRecord *)DBPropGet(def, cmd->tx_argv[argstart], &propfound);
 	if (propfound)
@@ -2469,6 +2489,25 @@ CmdDoProperty(
     }
     else if (locargc >= 3)
     {
+	/* If the property type was "compat", then set the state of the
+	 * compatibility flag and return.
+	 */
+	if (proptype == PROPERTY_TYPE_COMPAT)
+	{
+	    int idx;
+	    static const char * const cmdPropYesNo[] = {
+			"disable", "no", "false", "off", "0",
+			"enable", "yes", "true", "on", "1", 0 };
+	    idx = Lookup(cmd->tx_argv[2], cmdPropYesNo);
+	    if (idx < 0)
+	    {
+		TxError("Unknown property compat option \"%s\"\n", cmd->tx_argv[2]);
+		return;
+	    }
+	    DBPropCompat = (idx <= 4) ? FALSE : TRUE;
+	    return;
+	}
+
 	/* Catch the following known reserved keywords and cast them to the
 	 * expected property type.  If any property type was already given
 	 * to the command, it is overridden.  This ensures that the reserved
diff --git a/database/DBio.c b/database/DBio.c
index 3ac62654..f30c4546 100644
--- a/database/DBio.c
+++ b/database/DBio.c
@@ -2508,7 +2508,8 @@ dbReadProperties(cellDef, line, len, f, scalen, scaled)
 		/* handled as a dimension to avoid parsing the string	*/
 		/* value every time the coordinates are needed.		*/
 
-		if (!strcmp(propertyname, "FIXED_BBOX"))
+		if ((!strcmp(propertyname, "FIXED_BBOX")) ||
+			(!strcmp(propertyname, "OBS_BBOX")))
 		{
 		    Rect locbbox;
 
@@ -2546,7 +2547,8 @@ dbReadProperties(cellDef, line, len, f, scalen, scaled)
 			    locbbox.r_xtop /= scaled;
 			    locbbox.r_ytop /= scaled;
 			}
-			cellDef->cd_flags |= CDFIXEDBBOX;
+			if (propertyname[0] == 'F')
+			    cellDef->cd_flags |= CDFIXEDBBOX;
 
 			proprec = (PropertyRecord *)mallocMagic(
 				sizeof(PropertyRecord) + 2 * sizeof(int));
@@ -4090,20 +4092,32 @@ dbWritePropFunc(key, proprec, cdata)
     int i;
     char newvalue[20];
 
-    switch (proprec->prop_type)
+    /* In "compatibility" mode, always write "string" to the output.
+     * this has no adverse effects other than marginally slower
+     * read-in of .mag files with properties, but it keeps the .mag
+     * file format compatible with earlier versions of magic.
+     */
+    if (DBPropCompat)
     {
-	case PROPERTY_TYPE_STRING:
-	    FPUTSR(f, "string ");
-	    break;
-	case PROPERTY_TYPE_INTEGER:
-	    FPUTSR(f, "integer ");
-	    break;
-	case PROPERTY_TYPE_DIMENSION:
-	    FPUTSR(f, "dimension ");
-	    break;
-	case PROPERTY_TYPE_DOUBLE:
-	    FPUTSR(f, "double ");
-	    break;
+	FPUTSR(f, "string ");
+    }
+    else
+    {
+	switch (proprec->prop_type)
+	{
+	    case PROPERTY_TYPE_STRING:
+		FPUTSR(f, "string ");
+		break;
+	    case PROPERTY_TYPE_INTEGER:
+		FPUTSR(f, "integer ");
+		break;
+	    case PROPERTY_TYPE_DIMENSION:
+		FPUTSR(f, "dimension ");
+		break;
+	    case PROPERTY_TYPE_DOUBLE:
+		FPUTSR(f, "double ");
+		break;
+	}
     }
     FPUTSR(f, key);
 
diff --git a/database/DBprop.c b/database/DBprop.c
index 5be3c6ca..f44ffecc 100644
--- a/database/DBprop.c
+++ b/database/DBprop.c
@@ -32,6 +32,16 @@ static char rcsid[] __attribute__ ((unused)) = "$Header: /usr/cvsroot/magic-8.0/
 #include "database/database.h"
 #include "utils/malloc.h"
 
+/* Global variable */
+
+bool DBPropCompat = TRUE;	/* If TRUE, then always save properties to
+				 * .mag files as type "string" for backwards
+				 * compatibility.  If FALSE, then properties
+				 * are saved to the .mag file along with their
+				 * type.  Regardless of the setting, properties
+				 * which are reserved keywords are converted
+				 * to the best internal representation on input.
+				 */
 
 /* ----------------------------------------------------------------------------
  *
diff --git a/database/database.h.in b/database/database.h.in
index 07742730..45939459 100644
--- a/database/database.h.in
+++ b/database/database.h.in
@@ -1046,6 +1046,7 @@ extern int DBLambda[2];
 /* -------------------- Exported magic file suffix -------------------- */
 
 extern char *DBSuffix;		/* Suffix appended to all Magic cell names */
+extern bool DBPropCompat;	/* Backwards-compatible properties */
 
 /* -------------------- User Interface Stuff -------------------------- */
 
diff --git a/doc/html/property.html b/doc/html/property.html
index 4f4c0348..c7277e9f 100644
--- a/doc/html/property.html
+++ b/doc/html/property.html
@@ -25,7 +25,9 @@ Attach a "property" (string key and value pair) to the edit cell
 
 <H3>Usage:</H3>
    <BLOCKQUOTE>
-      <B>property</B> [<I>type</I>] [<I>key</I> [<I>value</I>]] <BR><BR>
+      <B>property</B> [<I>type</I>] [<I>key</I> [<I>value</I>]] <BR>
+	or
+      <B>property</B> [<B>compat</B>] [<B>true</B>|<B>false</B>] <BR><BR>
       <BLOCKQUOTE>
          where <I>key</I> and <I>value</I> are any text strings. <BR>
 	 <I>type</I> may be one of <B>string</B>, <B>integer</B>,
@@ -52,7 +54,16 @@ Attach a "property" (string key and value pair) to the edit cell
       By default, properties are interpreted as verbatim string values,
       with exceptions for the reserved types (see below).  To force the
       values of the property to be interpreted as a specific type, use
-      the <I>type</I> option.
+      the <I>type</I> option. <P>
+
+      The <B>property compat</B> setting determines how properties are
+      written out to a .mag file.  The default setting is <B>true</B>
+      (backwards compatibility mode), which writes all properties as
+      type "<TT>string</TT>".  Properties which are reserved names
+      (see below) will be converted to the best type when reading the
+      .mag file.  However, if the user wants to create a property that
+      is handled differently than a string (namely, to be a dimensional
+      value that scales), then comptability mode should be turned off. <P>
    </BLOCKQUOTE>
 
    <BLOCKQUOTE>