A Maryland Request for Service/Order for Service/Proof of Service is a legal document used to prove that a party has been formally served with legal documents. It is also referred to as service of process. The three types of Maryland Request for Service/Order for Service/Proof of Service are: 1. Request for Service: A Request for Service is a document used to request that the court order a particular entity to serve legal documents to a party. 2. Order for Service: An Order for Service is a document issued by a court in response to a Request for Service. It orders a particular entity to serve legal documents to a party. 3. Proof of Service: A Proof of Service is a document that confirms that legal documents were successfully served to a party. It is typically signed by the person or entity that served the documents.