The semantics of matching search query terms to result text containing non-alphanumeric characters are described in this topic.
During query processing, each user query term is transformed to replace all non-alphanumeric characters that are not marked as search characters with delimiters (spaces).
Non-alphanumeric characters considered to be punctuation (! @ # & ( ) – [ { } ] : ; ', ? / *) are treated as white space and preserve word order. This means that the equivalent of a quoted phrase search is generated. For that reason, all search features that are incompatible with quoted phrase search, such as spelling correction, stemming, and thesaurus expansion, are not activated. (For details, see the "Using Phrase Search" chapter.)
Non-alphanumeric characters that are considered to be symbols (` ~ $ ^ + = < > “) are also treated as white space. However, unlike punctuation characters, they do not preserve word order in a multi-word search.
Alphabetic characters in the user query are replaced with lowercase equivalents, to ensure that they match against case-folded indexed strings.
Each query term in the transformed query must exactly match some indexed string from the given source text for the text to be considered a hit.
As noted above, when parsing user-entered search terms, a query with non-searchable characters is transformed to replace all non-alphanumeric characters (that are not marked as search characters) with white space, but the treatment of word order depends on whether the character in question is considered to be a punctuation character or a symbol. The search behavior preserves the word order and proximity of the search term only in the case of punctuation characters.
For example, a search query for ice-cream will replace the hyphen (a punctuation character) with white space and return only records with this text:
Records with this text are not returned because the word order and word proximity of text does not match the original query term:
However, assuming the match mode is MatchAll, a search for ice~cream would return non-contiguous results for [ice AND cream].
