2.2.10.4 Keyword Inclusion

If a token is preceded by a plus character, the items MUST match that part of the search query if they contain the token. This syntax only makes sense for queries where the ImplicitAndBehavior element in the QueryPacket is set to false. It MUST be ignored otherwise.

This feature MUST NOT be combined with the phrasal matching feature. The results of the search query "trek +"mirror universe"" are undefined.