You can use the "||" operator for seperating multiple values.
(i.e. "tP6||mP12" means "tP6" OR "mP12")
Properties with empty values will be ignored.
You can use the "%" operator for wildcard.
(i.e. an author name specification with "M%" will match any entry that has an author surname starting with "M". It also matters where you place the "%" operator (Left, right, or both sites for left and right completition).
The search criteria are joined with the AND operator.