The semantics of matching search queries to text containing special non-alphanumeric characters in the Oracle Commerce MDEX Engine is based on indexing various forms of source text containing such characters.

Basically, user query terms are required to match exactly against indexed forms of the words in the source text to result in matches. Thus, to understand the behavior of query matching in the presence of non-alphanumeric characters, one must understand the set of forms indexed for source text.