Board Rules is what new user registrations see and accept just before registering for a new account. It is also displayed in the footer as a link (just as you've said in the op)
You can customize the information on that page using HTML code, such as br, color, size...etc. all the normal HTML stylings.
this can be done at
Control Panel > Membership Registration > Board Rules.
If you wanted to manually edit the footer template file so Board Rules no longer links to the Board Rules you've written, you can edit the /templates/default/footer.tpl file. but editing stock template files is not supported by this support forum, and any customizations you make to the template files will probably be lost when you update your forum software to a future version... So if you go this route, make a note of your custom changes.
