diff --git a/cangw.c b/cangw.c
index 041a0a4..bf45331 100644
--- a/cangw.c
+++ b/cangw.c
@@ -240,7 +240,7 @@ void print_usage(char *prg)
 	fprintf(stderr, "          -u <uid>  (user defined modification identifier)\n");
 	fprintf(stderr, "          -l <hops>  (limit the number of frame hops / routings)\n");
 	fprintf(stderr, "          -f <filter>  (set CAN filter)\n");
-	fprintf(stderr, "          -m <mod>  (set Classic CAN frame modifications)\n");
+	fprintf(stderr, "          -m <mod>  (set Classical CAN frame modifications)\n");
 	fprintf(stderr, "          -M <MOD>  (set CAN FD frame modifications)\n");
 	fprintf(stderr, "          -x <from_idx>:<to_idx>:<result_idx>:<init_xor_val>  (XOR checksum)\n");
 	fprintf(stderr, "          -c <from>:<to>:<result>:<init_val>:<xor_val>:<crctab[256]>  (CRC8 cs)\n");
@@ -251,12 +251,12 @@ void print_usage(char *prg)
 	fprintf(stderr, "  <can_id>:<can_mask>  (matches when <received_can_id> & mask == can_id & mask)\n");
 	fprintf(stderr, "  <can_id>~<can_mask>  (matches when <received_can_id> & mask != can_id & mask)\n");
 	fprintf(stderr, "\n");
-	fprintf(stderr, "<mod> is a CAN frame modification instruction consisting of\n");
+	fprintf(stderr, "<mod> is a Classical CAN frame modification instruction consisting of\n");
 	fprintf(stderr, "<instruction>:<can_frame-elements>:<can_id>.<can_dlc>.<can_data>\n");
 	fprintf(stderr, "  <instruction>  is one of 'AND' 'OR' 'XOR' 'SET'\n");
 	fprintf(stderr, "  <can_frame-elements>  is _one_ or _more_ of 'I'dentifier 'L'ength 'D'ata\n");
 	fprintf(stderr, "  <can_id>  is an u32 value containing the CAN Identifier\n");
-	fprintf(stderr, "  <can_dlc>  is an u8 value containing the data length code (0 .. 8)\n");
+	fprintf(stderr, "  <can_dlc>  is an u8 value containing the data length code in hex (0 .. F)\n");
 	fprintf(stderr, "  <can_data>  is always eight(!) u8 values containing the CAN frames data\n");
 	fprintf(stderr, "\n");
 	fprintf(stderr, "<MOD> is a CAN FD frame modification instruction consisting of\n");
@@ -265,7 +265,7 @@ void print_usage(char *prg)
 	fprintf(stderr, "  <canfd_frame-elements>  is _one_ or _more_ of 'I'd 'F'lags 'L'ength 'D'ata\n");
 	fprintf(stderr, "  <can_id>  is an u32 value containing the CAN FD Identifier\n");
 	fprintf(stderr, "  <flags>  is an u8 value containing CAN FD flags (CANFD_BRS, CANFD_ESI)\n");
-	fprintf(stderr, "  <len>  is an u8 value containing the data length (0 .. 64)\n");
+	fprintf(stderr, "  <len>  is an u8 value containing the data length in hex (0 .. 40)\n");
 	fprintf(stderr, "  <can_data>  is always 64(!) u8 values containing the CAN FD frames data\n");
 	fprintf(stderr, "The max. four modifications are performed in the order AND -> OR -> XOR -> SET\n");
 	fprintf(stderr, "\n");
diff --git a/include/linux/can/gw.h b/include/linux/can/gw.h
index c2190bb..e4f0957 100644
--- a/include/linux/can/gw.h
+++ b/include/linux/can/gw.h
@@ -98,8 +98,8 @@ enum {
 
 /* CAN frame elements that are affected by curr. 3 CAN frame modifications */
 #define CGW_MOD_ID	0x01
-#define CGW_MOD_DLC	0x02		/* contains the data length in bytes */
-#define CGW_MOD_LEN	CGW_MOD_DLC	/* CAN FD length representation */
+#define CGW_MOD_DLC	0x02		/* Classical CAN data length code */
+#define CGW_MOD_LEN	CGW_MOD_DLC	/* CAN FD (plain) data length */
 #define CGW_MOD_DATA	0x04
 #define CGW_MOD_FLAGS	0x08		/* CAN FD flags */