diff --git a/include/cdio/mmc.h b/include/cdio/mmc.h
index c23950a1..ac8f3964 100644
--- a/include/cdio/mmc.h
+++ b/include/cdio/mmc.h
@@ -86,38 +86,63 @@ extern "C" {
 	uint8_t asb[46];              /**< Additional sense bytes */
     } mmc_request_sense_t;
 
-  /**
-      Set this to the maximum value in milliseconds that we will
-      wait on an MMC command.  
-  */
-  extern uint32_t mmc_timeout_ms; 
 
-  /**
-      The default timeout (non-read) is 6 seconds. 
-  */
+    /**
+       Meanings of the values of mmc_request_sense.sense_key
+     */
+    typedef enum {
+        MMC_SENSE_KEY_NO_SENSE        =  0,
+        MMC_SENSE_KEY_RECOVERED_ERROR =  1,
+        MMC_SENSE_KEY_NOT_READY       =  2,
+        MMC_SENSE_KEY_MEDIUM_ERROR    =  3,
+        MMC_SENSE_KEY_HARDWARE_ERROR  =  4,
+        MMC_SENSE_KEY_ILLEGAL_REQUEST =  5,
+        MMC_SENSE_KEY_UNIT_ATTENTION  =  6,
+        MMC_SENSE_KEY_DATA_PROTECT    =  7,
+        MMC_SENSE_KEY_FIRMWARE_ERROR  =  9,
+        MMC_SENSE_KEY_ABORTED_COMMAND = 11,
+        MMC_SENSE_KEY_EQUAL           = 12,
+        MMC_SENSE_KEY_VOLUME_OVERFLOW = 13,
+        MMC_SENSE_KEY_MISCOMPARE      = 14,
+    } mmc_sense_key_t;
+
+   /**
+      Maps a mmc_sense_key_t into a string name.
+   */
+    extern const char mmc_sense_key2str[16][40];
+
+    /**
+       Set this to the maximum value in milliseconds that we will
+       wait on an MMC command.  
+    */
+    extern uint32_t mmc_timeout_ms; 
+
+    /**
+       The default timeout (non-read) is 6 seconds. 
+    */
 #define MMC_TIMEOUT_DEFAULT 6000
 
-  /**
-      Set this to the maximum value in milliseconds that we will
-      wait on an MMC read command.  
-  */
-  extern uint32_t mmc_read_timeout_ms;
-
-  /** The default read timeout is 3 minutes. */
-#define MMC_READ_TIMEOUT_DEFAULT 3*60*1000
-
-  /**
-      \brief The opcode-portion (generic packet commands) of an MMC command.
+    /**
+       Set this to the maximum value in milliseconds that we will
+       wait on an MMC read command.  
+    */
+    extern uint32_t mmc_read_timeout_ms;
     
-      In general, those opcodes that end in 6 take a 6-byte command
-      descriptor, those that end in 10 take a 10-byte
-      descriptor and those that in in 12 take a 12-byte descriptor. 
-      
-      (Not that you need to know that, but it seems to be a
-      big deal in the MMC specification.)
-  
-  */
-  typedef enum {
+    /** The default read timeout is 3 minutes. */
+#define MMC_READ_TIMEOUT_DEFAULT 3*60*1000
+    
+    /**
+       \brief The opcode-portion (generic packet commands) of an MMC command.
+       
+       In general, those opcodes that end in 6 take a 6-byte command
+       descriptor, those that end in 10 take a 10-byte
+       descriptor and those that in in 12 take a 12-byte descriptor. 
+       
+       (Not that you need to know that, but it seems to be a
+       big deal in the MMC specification.)
+       
+    */
+    typedef enum {
   CDIO_MMC_TEST_UNIT_READY              = 0x00, /**< Request drive 
                                                    information. */
   CDIO_MMC_GPCMD_INQUIRY                = 0x12, /**< Request drive 
diff --git a/lib/driver/mmc.c b/lib/driver/mmc.c
index 23a588e3..49416ab8 100644
--- a/lib/driver/mmc.c
+++ b/lib/driver/mmc.c
@@ -42,6 +42,28 @@
 #include <errno.h>
 #endif
 
+/**
+   Maps a mmc_sense_key_t into a string name.
+ */
+const char mmc_sense_key2str[16][40] = {
+    "No Sense",              /**< 0 No specific Sense Key info reported */
+    "Recovered Error",       /**< 1 Completed ok with recovery */
+    "Not Ready",             /**< 2 */
+    "Medium Error",          /**< 3 */
+    "Hardware Error",        /**< 4 */
+    "Illegal Request",       /**< 5 */
+    "Unit Attention",        /**< 6 */
+    "Data Protect",          /**< 7 */
+    "Blank/Nonblank",        /**< 8 */
+    "Firmware Error",        /**< 9  - Vendor-specific */
+    "Copy aborted",          /**< A */
+    "Aborted Command",       /**< B */
+    "Equal",                 /**< C */
+    "Volume Overflow",       /**< D */
+    "Miscompare",            /**< E */
+    "(reserved error code)", /**< F */
+};
+
 /** The below variables are trickery to force enum symbol values to be
     recorded in debug symbol tables. They are used to allow one to refer
     to the enumeration value names in the typedefs above in a debugger