diff --git a/src/include/86box/scsi_device.h b/src/include/86box/scsi_device.h
index b1f0a8abd..4c2ff95ac 100644
--- a/src/include/86box/scsi_device.h
+++ b/src/include/86box/scsi_device.h
@@ -163,22 +163,24 @@
 #define GPCMD_PLAY_AUDIO_TRACK_RELATIVE_12_MATSUSHITA 0xe9 /* Matsushita Vendor Unique command */
 
 /* Mode page codes for mode sense/set */
-#define GPMODE_UNIT_ATN_PAGE         0x00
-#define GPMODE_R_W_ERROR_PAGE        0x01
+#define GPMODE_UNIT_ATN_PAGE         0x00 /* Unit Attention page */
+#define GPMODE_R_W_ERROR_PAGE        0x01 /* Read-Write Error Recovery page */
 #define GPMODE_DISCONNECT_PAGE       0x02 /* Disconnect/reconnect page */
-#define GPMODE_FORMAT_DEVICE_PAGE    0x03
+#define GPMODE_FORMAT_DEVICE_PAGE    0x03 /* Format device page */
 #define GPMODE_RIGID_DISK_PAGE       0x04 /* Rigid disk geometry page */
-#define GPMODE_FLEXIBLE_DISK_PAGE    0x05
-#define GPMODE_CACHING_PAGE          0x08
-#define GPMODE_CDROM_PAGE_SONY       0x08
-#define GPMODE_CDROM_AUDIO_PAGE_SONY 0x09
-#define GPMODE_CDROM_PAGE            0x0d
-#define GPMODE_CDROM_AUDIO_PAGE      0x0e
-#define GPMODE_CAPABILITIES_PAGE     0x2a
-#define GPMODE_IOMEGA_PAGE           0x2f
-#define GPMODE_IMATION_PAGE          0x2f
-#define GPMODE_UNK_VENDOR_PAGE       0x30
-#define GPMODE_ALL_PAGES             0x3f
+#define GPMODE_FLEXIBLE_DISK_PAGE    0x05 /* Flexible disk page */
+#define GPMODE_CACHING_PAGE          0x08 /* Caching page */
+#define GPMODE_CDROM_PAGE_SONY       0x08 /* Sony-specific CD-ROM page */
+#define GPMODE_CDROM_AUDIO_PAGE_SONY 0x09 /* Sony-specific CD-ROM audio page */
+#define GPMODE_MEDIUM_TYPES_PAGE     0x0b /* Medium types supported page */
+#define GPMODE_CDROM_PAGE            0x0d /* General CD-ROM page */
+#define GPMODE_CDROM_AUDIO_PAGE      0x0e /* General CD-ROM audio page */
+#define GPMODE_REMOVABLE_BLOCK_ACCESS_PAGE 0x1b /* Removable block access capabilities page */
+#define GPMODE_CAPABILITIES_PAGE     0x2a /* Capabilities page */
+#define GPMODE_IOMEGA_PAGE           0x2f /* Iomega-specific page */
+#define GPMODE_IMATION_PAGE          0x2f /* Invalid - To be removed */
+#define GPMODE_UNK_VENDOR_PAGE       0x30 /* Unknown vendor-specific page */
+#define GPMODE_ALL_PAGES             0x3f /* All pages supported */
 
 /* Mode page codes for presence */
 #define GPMODEP_UNIT_ATN_PAGE         0x0000000000000001LL