Negative keywords
This means your ad will be shown when anyone searches for your Keywords, unless the search phrase also includes your Negative Keywords. To activate Negative Keywords, you type the Keywords in the input box with a minus symbol directly in front of the words (with no space).
Example
Keyword: history of photography
Negative Keyword: Russian
The ad will be shown for every phrase as in the Broad Match above, but not if someone searches for
history of Russian photography
Russian photography of history
etc.
Our recommendation is to develop your Keywords using Broad Match (the default option), with Negative Keywords to take away irrelevant search phrases, as determined by the Keyword Research Procedure.