I haven't seen any restrictions, but I don't think they are a good idea. I don't look in those threads, as I think it is a mild form of merit begging. I question the reason that the member wants the merit in the first place. The idea behind rewarded and encouraged for their posting content, and for their support of merit worthy threads. If we need to have these threads, then it means that there aren't enough merit worthy threads, or that the merit awarders aren't visiting them. In either case, we should address the problem, rather than taking the easy way out by checking the self-promotion lists.

There must be many new and junior members who have questions about Bitcoin and the Bitcoin economy. We need to encourage them to bring these to the board for discussion. Of course if the question is very basic, and can be solved with a simple Google search, then that won't provide great value to the forum. Always assuming that the Google answer can't be questioned.