-MOUSEKEY_ENABLE = yes # Mouse keys
-EXTRAKEY_ENABLE = yes # Media control and System control
-CONSOLE_ENABLE = yes # Console for debug
-#NKRO_ENABLE = yes # USB Nkey Rollover
+MOUSEKEY_ENABLE ?= yes # Mouse keys
+EXTRAKEY_ENABLE ?= yes # Media control and System control
+CONSOLE_ENABLE ?= yes # Console for debug
+#COMMAND_ENABLE ?= yes # Commands for debug and configuration
+#NKRO_ENABLE ?= yes # USB Nkey Rollover