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working on something.

  /----- Server, implemented in ttt-server
 / /---- Client, implemented in ttt
S C
    1. Requests
✓   1.1 HELO
✓   1.2. Global commands
✓   1.2.1. WHO
✓   1.2.2. MESSAGE
✓   1.2.3. HELP
✓   1.2.4. QUIT
✓   1.2.5. VERSION
    1.3. Game management commands
    1.3.1. INVITE
    1.3.2. ACCEPT
    1.4. In-game commands
    1.4.1. SHOW
    1.4.2. PART
    1.4.3. MOVE
    2. Asynchronous notification.  
    2.1. Global notices
✓   2.1.1. NOTICE USER <username>
✓   2.1.2. NOTICE QUIT <username>
    2.1.3. NOTICE INVITE <username>
    2.1.4. NOTICE DISPOSE <game>
✓   2.1.5. NOTICE MESSAGE <username> <text>
    2.2. Game notices
    2.2.1. Global game notices
    2.2.1.1. NOTICE NEWGAME <username> <username>
    2.2.1.2. NOTICE GAMEOVER <outcome> <username>
    2.2.2. Move notices
    2.2.2.1. NOTICE MOVE <username> <number>
    3. Errors
    3.1. Connection setup errors
✓   3.1.1. ERROR NONAMESET
✓   3.1.2. ERROR INVALIDNAME
    3.2. Command format errors
    3.2.1. ERROR COMMAND
✓   3.2.2. ERROR SYNTAX
    3.2.3. ERROR NOTNUMBER
    3.2.4. ERROR NOTGRID
    3.3. Global command errors.
    3.4. Game management errors.
    3.4.1. ERROR NOGAME
    3.5. User information errors
    3.5.1. ERROR NOUSER
    3.6. In-game errors
    3.6.1. Global game errors
    3.6.1.1. ERROR NOTINGAME
    3.6.1.2. ERROR NOTPLAYING
    3.6.2. Moving errors 
    3.6.2.1. ERROR NOTYOURTURN