1. A parser for handling context information associated with a message flow in a messaging system, the message flow having processing nodes for processing the message and wherein at least part of the message has been parsed into a logical representation accessible by processing nodes in the message flow and wherein context information used by the message flow to process the message has been converted into a logical representation accessible by at least one processing node in the message flow, the parser comprising: means for receiving at the parser a request to perform an operation associated with the message, the message having been processed by at least part of the message flow; and means for ignoring the logical representation of context information associated with the processing of said message, said logical representation of the context information co-existing with the logical representation of at least part of that message.