It would be nice to have control over what bots are allowed to index.
Currently one can use the following in the global header
<META NAME="ROBOTS" CONTENT="NOINDEX, NOFOLLOW">
This will stop bots from indexing anything, but sometimes it is good to have the main page and the first board page being indexed.
There is currently no way to fine-tune this, since all the board pages use the main page header.
So for the main page one would allow bots to follow links and to index it.
For the boards only indexing would be allowed, following links would be not.