Why remove [[ ... [[ ... ]] ... ]]

["mos" <mmosquito@...>]

Hi!
    From 5.02 to 5.1, it can not surpport the string like [[abc[[def]]ghl]], I indeed have the requirement because I use Lua as the RPC's parser.
    I like [[ ]], it have begin and end so can use it freely.
    for example: I send a cmd to server like 
    "DoCmd([[ShutDown([[the server will shut down!]])]])"; 
    and more 
    SendCmdRemote("topserver", [[DoCmd([[ShutDown([[the server will shut down!]])]]]]) 
    and I feel very sad when use [=[ ]=] etc. How can I know how many '=' I should append?

yujiang