US Patent 8375042 Index-side synonym generation

Methods, systems, and apparatus, including computer programs encoded on computer storage media, for index-side synonym expansion. One method includes indexing a token from a resource, including determining that the token comprises a numeric portion and storing data associating the resource with both the particular token and the numeric portion in a search engine index. Another method includes indexing a token from a resource, including normalizing the token by removing a prefix matching a stopword prefix and storing data associating the resource with both the token and the normalized form of the token in a search engine index. Another method includes creating a token blacklist.