These rules are all based on the URL of the page you want or do not want the block to show up on. The custom display options gives you some basic options -- all, portal, forum, sforum, allaction, allboards. Then it gives you ways to specify different parts of the page's URL. SMF URLs use a query string. The query string starts with ?. The ? is followed by a parameter. A parameter might be followed by an equals sign (=) and a value. A parameter (and its value, if it has one), can be followed by a semi-colon (;). The semicolon is followed by another parameter, and so on, until the end of the query string. Some common SMF parameters are action, topic, board, sa. Some examples of parameters that mods might provide are game, album, etc
The custom display rules let you specify a parameter, optionally a value, and even allow you to say "only if that is NOT the case", if you wish.
Using a parameter
You may use the "basic" parameters -- all, portal, forum, sforum, allaction, allboards. If you want to be specific, though, you can use the tilde, or wavy, to give a rule for a parameter you choose.
- ~board -- block will show whenever board appears as a parameter in the query string
- ~game -- block will show whenever game appears as a parameter in the query string
If you want to show the block only when the parameter has a certain value (board=10.0, album=99, game=uno), then you must use the pipe or idkin character |. It is standing in for an equals sign (=).
- ~board|10.0 -- block will show only when board=10.0 appears in the query string.
- ~game|uno -- block will show only when game=uno appears in the query string
The minus sign acts as the negator.
- -~action|post -- don't show this block when starting or editing a post (topic or reply)
- -~board|12.0 -- don't show this block for board 12
You can use multiple rules for one block. Just separate them with a comma (,).
- ~board|10.0 -- the block will show up whenever "board=10.0" appears in the query string. Even when you start a new topic on that board!
- ~board|10.0, -~action|post -- the block will show up whenever "board=10.0" appears in the query string. Except, it won't appear whenever "action=post" appears in the query string. So you won't see it when you start a new topic on the board (or any other board)