Search Stop Words in the National Service Center for Environmental Publications
In all instances, be careful to avoid common words, referred to as "stop" words. The system will not prevent their use in a query but will generate an error message if they are not removed.
When you remove a "stop" word, you will need to add an "and" in place of the removed "stop" word. This will let the database search the field properly. If you do not add the "and" in place of the "stop" word you removed, you will get a ‘No documents found’ result. For example, if you are searching for the title: Compilation of Air Pollutant Emission Factors", you would type in the title field: "Compilation and Air Pollutant Emission Factors".
In addition to the list below, single alphabet characters are also considered stop words but numbers are not.