--- /dev/null
+--- sys.stable/net/if_ppp.h Sat Oct 18 04:02:39 1997
++++ /usr/src/synclink/bsd3/if_ppp.h Fri Apr 16 12:54:12 1999
+@@ -53,6 +53,7 @@
+ #define SC_RCV_B7_1 0x02000000 /* have rcvd char with bit 7 = 1 */
+ #define SC_RCV_EVNP 0x04000000 /* have rcvd char with even parity */
+ #define SC_RCV_ODDP 0x08000000 /* have rcvd char with odd parity */
++#define SC_SYNC 0x00200000 /* synchronous HDLC */
+ #define SC_MASK 0x0fff00ff /* bits that user can change */
+
+ /*