(a) the customer concerned has informed the customer in writing that the customer in question has concluded a contract for the provision of distribution services with an authorised distributor; or after receiving a complete connection request, AEMO creates a connection offer. If a declared common network (DSN) extension is required, the contracts required for the connection can be quite complex. Use of System Agreement (UoSA) documents AEMO`s connection offer, which is usually accompanied by a number of other contracts in an executable form and which meet, among other things, the formal requirements for connection and network agreements. Their number, form and execution time vary depending on whether the gas can be injected into the system or purchased by the wholesale gas market. When injecting gas, an allocation agent may be required at each injection site.