diff --git a/avrdude/Usage b/avrdude/Usage
index c18f0d2f..ff5ee81f 100644
--- a/avrdude/Usage
+++ b/avrdude/Usage
@@ -4,7 +4,7 @@ Usage:  avrprog [options]
 
     -m MemType    : select memory type for reading or writing
                       \"e\", \"eeprom\" = EEPROM
-                      \"f\", \"flash\"  = FLASH
+                      \"f\", \"flash\"  = FLASH (default)
 
     -i Filename   : select input file, \"-\" = stdin
 
@@ -13,8 +13,10 @@ Usage:  avrprog [options]
     -f Format     : select input / output file format
                       \"i\" = Intel Hex
                       \"s\" = Motorola S-Record
-                      \"r\" = Raw binary
-                      \"a\" = Auto detect (valid input only)
+                      \"r\" = Raw binary (default for output)
+                      \"a\" = Auto detect (default for input)
+                              (valid for input only)
+                              
 
     -p Part       : select Atmel part number (see below for valid parts)
 
diff --git a/avrdude/avrprog.c b/avrdude/avrprog.c
index 8bce0448..b1a8964e 100644
--- a/avrdude/avrprog.c
+++ b/avrdude/avrprog.c
@@ -164,7 +164,7 @@ char * usage_text =
 "\n"
 "    -m MemType    : select memory type for reading or writing\n"
 "                      \"e\", \"eeprom\" = EEPROM\n"
-"                      \"f\", \"flash\"  = FLASH\n"
+"                      \"f\", \"flash\"  = FLASH (default)\n"
 "\n"
 "    -i Filename   : select input file, \"-\" = stdin\n"
 "\n"
@@ -173,8 +173,10 @@ char * usage_text =
 "    -f Format     : select input / output file format\n"
 "                      \"i\" = Intel Hex\n"
 "                      \"s\" = Motorola S-Record\n"
-"                      \"r\" = Raw binary\n"
-"                      \"a\" = Auto detect (valid input only)\n"
+"                      \"r\" = Raw binary (default for output)\n"
+"                      \"a\" = Auto detect (default for input)\n"
+"                              (valid for input only)\n"
+"                              \n"
 "\n"
 "    -p Part       : select Atmel part number (see below for valid parts)\n"
 "\n"