Stop words are frequently used words that do not carry a semantic meaning and can be removed from an index to reduce its size.
You can enable or disable the use of stop words by calling the setUseStopWords method of the IndexSettings class. The default value is true, meaning that stop words are filtered during indexing and not added to the index.
A list of stop words to use during indexing can be specified in the stop word Dictionary....stop word dictionary. By default, the stop word dictionary is filled...on managing the stop word dictionary, see the page in the section...