+ TTT_ERROR_NOT_NUMBER,
+ TTT_ERROR_NOT_GRID,
+ /* 3.3. Global command errors */
+ /* 3.4. Game management errors */
+ TTT_ERROR_NO_INVITE,
+ TTT_ERROR_NO_GAME,
+ /* 3.5. User information errors */
+ TTT_ERROR_NO_USER,
+ /* 3.6. In-game errors */
+ TTT_ERROR_NOT_PLAYING,
+ TTT_ERROR_NOT_YOUR_TURN,
+ TTT_ERROR_NOT_VALID_MOVE,
+
+ /* Here's a non-protocol pseudo-error used to implement QUIT. */
+ TTT_ERROR_QUIT_REQUESTED