This variable applies only in a thin client environment. SERVER_ALIAS_FILE holds the name of the alias file to be used with the thin client. When the thin client is invoked, it is not given the name of a COBOL program to run. Rather, it is given the name of an alias to use. This alias holds all the information for invoking the runtime, which will be used to run the COBOL program. See Creating a Server Alias File in Thin Client for information on creating the server alias file.