Creation of child boards within Off-Topic would certainly make the board more readable. The child-boards could range from Technical Stuffs, Daily Routine, Netizens life goings and a lot more. These are some of the widely discussed topics in the Off-Topic board when I at least visit them once in a week.
I won't second a child board suggestion for the board reason been that we already have far too many child board which are almost inactive and won't be a great idea to add another to a section that's hardly visited by forum users. If you have some bitcoin related offtopic you want to discuss, i don't see any problem discussing it on the board, as the description suggestion, all off topic discuss are welcome on the board.
Also you can create those topics on the serious discussion board and it would be find there, if it's worthy to be classified as a serious discussion considering it's bitcoin related and some offtopic could still be considered as serious topics.. Although it'll still be a nice idea for those topics to be created on the offtopic board to add some quality to the board.
