If you are looking for the search settings, see Search (admin) (en)
Assuming the forum is running the SMF default theme (or a derivative of it), there should be both a simple Search field in the collapsible header and a Search link in the main menu. If not, the main menu Search link should still lead straight to the advanced search screen given permission to search is given.
While you can just type (and search for) any combination of characters, you should consider using modifiers to make your search really work for you.
The simple search field located at the top of the default SMF theme will, when viewing topics filter search results to just that topic. The same thing goes for boards as well, when viewing a board the simple search field will filter what you searched to just results in that particular board.
To use the simple search (if Advanced is not enabled), the basic syntax outlined above is all you really need to know. But you might also like to know that this tool searches the entire forum (en) for any or all of what you specify that's been posted during the last 9999 days (which is more than 27 years)! So, to take more control of your search, you should use the advanced search feature.
Although the advanced search screen might initially seem a little intimidating if a forum has many boards and child boards, it's surprisingly straightforward when reduced to its basic components.
- Despite initial appearances, there are really three options for how to search, with Match all words and Match any words being available from the drop-down, and "Match as phrase" also an option.
- The default * in the by user field is essentially a wildcard matching any poster. Please note that, while you can replace this with any single username for a more specific search, it's not possible to search for posts by multiple users except as that single wildcard.
- Show results as messages returns the full message containing the search string (with a reply option) instead of the usual linked excerpt, but will naturally result in much larger results pages which might be significant if you are searching for a popular word or phrase.
- Message age sets the minimum and maximum ages of posts to search.
- Choose a board (en) to search in provides you with another tool to narrow the scope of the search, with the default being 'all' (the whole forum or, more properly, all the boards to which you have read access). To search by board you need to expand the list of boards by clicking on Choose a board to search in, or search all and select which boards to search in and check the correct box.
- The Search button not surprisingly sets the whole thing in motion, but hitting 'Enter' direct from any of the search fields is sometimes more convenient.
Using the simple or advanced search methods, you can still use search modifiers. That is, powerful special characters which modify the way SMF handles your search string.
- Phrase search - use double quotes (") around your term ("search term") to search for the search term as a phrase instead of individual words.
- Excluding terms - use a minus sign in front of terms you'd like to exclude from the search result. For instance, "search -term" will search for "search" but not "term". The minus sign must have a space prior to it.
More search modifiers may be found at Google's help page. Although, not all of them may be useful in SMF at the present time.
See Search (admin) (en) for options for the administrator to configure searching.