Indexing non-alphanumeric characters

How non-alphanumeric characters that are not defined as search characters are treated depends on whether they are considered punctuation characters or symbols.

Non-alphanumeric characters considered to be punctuation are treated as white space. In a multi-word search with the words separated by punctuation characters, word order is preserved as if it were a phrase search. The following characters are considered to be punctuation: ! @ # & ( ) – [ { } ] : ; ', ? / *
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. If a symbol character is adjacent to a punctuation character, the symbol character is ignored. That is to say, the combination of the symbol character and the punctuation character is treated the same as the punctuation character alone.
For example, a search on ice-cream would return the same results as a phrase search for "ice cream", while a search for ice~cream would return the same results as simply searching for ice cream. A search on ice-~cream would behave the same way as a search on ice-cream.

Symbol characters include the following: ` ~ $ ^ + = < > "