+Bitmap report descriptor sample:
+ 0x05, 0x01, // Usage Page (Generic Desktop),
+ 0x09, 0x06, // Usage (Keyboard),
+ 0xA1, 0x01, // Collection (Application),
+ // bitmap of modifiers
+ 0x75, 0x01, // Report Size (1),
+ 0x95, 0x08, // Report Count (8),
+ 0x05, 0x07, // Usage Page (Key Codes),
+ 0x19, 0xE0, // Usage Minimum (224),
+ 0x29, 0xE7, // Usage Maximum (231),
+ 0x15, 0x00, // Logical Minimum (0),
+ 0x25, 0x01, // Logical Maximum (1),
+ 0x81, 0x02, // Input (Data, Variable, Absolute), ;Modifier byte
+ // LED output report
+ 0x95, 0x05, // Report Count (5),
+ 0x75, 0x01, // Report Size (1),
+ 0x05, 0x08, // Usage Page (LEDs),
+ 0x19, 0x01, // Usage Minimum (1),
+ 0x29, 0x05, // Usage Maximum (5),
+ 0x91, 0x02, // Output (Data, Variable, Absolute),
+ 0x95, 0x01, // Report Count (1),
+ 0x75, 0x03, // Report Size (3),
+ 0x91, 0x03, // Output (Constant),
+ // bitmap of keys
+ 0x95, (REPORT_BYTES-1)*8, // Report Count (),
+ 0x75, 0x01, // Report Size (1),
+ 0x15, 0x00, // Logical Minimum (0),
+ 0x25, 0x01, // Logical Maximum(1),
+ 0x05, 0x07, // Usage Page (Key Codes),
+ 0x19, 0x00, // Usage Minimum (0),
+ 0x29, (REPORT_BYTES-1)*8-1, // Usage Maximum (),
+ 0x81, 0x02, // Input (Data, Variable, Absolute),
+ 0xc0 // End Collection
+where REPORT_BYTES is a report size in bytes.
+
+
+Considerations
+--------------
+Compatibility
+ boot protocol
+ minor/old system
+ Some BIOS doesn't send SET_PROTCOL request, a keyboard can't switch to boot protocol mode.
+ This may cuase a problem on a keyboard which uses other report than Standard.
+Reactivity
+ USB polling time
+ OS/Driver processing time