2.2.10.5 Property Searches
A sequence of the form "property:token" MUST be interpreted as a property search query. Items MUST match this expression if the specified property contains the specified token. If the property name contains whitespace characters, it MUST be enclosed in double quotes. The property specified in this way MUST be searchable with the full-text. If the specified property is not full-text searchable, the sequence MUST NOT be interpreted as a property search query but instead be interpreted simply as a sequence of tokens.
It is possible to search for a phrase in a single property as well. The format for this is "property: "phrase"". Items that contain the given phrase, as defined in section 2.2.10.2, in the given property MUST match this expression.
Finally, it is possible to negate a property search query by preceding the entire expression with a minus character.