A printer for printing on a web of record members such as labels, tags, etc. includes an interpreter and a memory for storing an application program. The interpreter is enabled or disabled by the receipt of a command. When enabled, the interpreter processes an application program to extract data from a received data stream and to construct one or more data packets in a predetermined printer control language to be sent to a parser. When the interpreter is disabled, the received data may be processed by an XML or PCL task and forwarded to the parser, bypassing the interpreter.