A pre-search is used for screening a proposed name. It’s essentially meant to search the database for exact-character matches for the name you’re looking for (although you can sometimes enter wildcards to broaden your search a bit). You can think of it as a “knock-out” search. If you find an exact match, your proposed name is knocked out of the running. If not, you can go on to the next step, which would be one of the full NUANS searches such as a corporate reservation name search or a trademark search. These full searches will find similar matches as well as exact matches.
The entire NUANS database is searched, including trademarks and company names from across the country (except Quebec), as well as current proposed corporate names. (When you do a certain kind of name search, a name reservation for incorporation is included. This is called a “name proposal” and it’s generally current for 90 days.)
Many search houses also include a pre-search, or prescreen, as one of their offerings, usually for a minimal fee or free of charge. Some search houses simply include a pre-search as the first step in their searching routine when you order a full NUANS report.