A Petri net-based modeling framework called Dan/Petri net (D/PN) is used to model Discrete Event Systems. And Controlled D/PN is one extension developed to explain the modeling of multiple and simultaneous control (MSC). This type of control is modeled through MSC subnets which are clusters of siphons. We present a specific symmetry and notation convention for MSC subnets, and when they allow the modeling of our MSC-logic they are called valid MSC subnets. The first and fundamental valid MSC subnet, called the ?c(q) subnet and used for Controlled D/PN, is presented together with one derivative valid MSC subnet of the fundamental subnet ?c(q).