Once a titles bank has been requested the system will actively manage it, getting the right version and switching versions as required by the current context i.e. the current event date and data type. Certain SUs are ``Context Setters''. During the execution phase, context setters are responsible for informing the MTT system of changes of context which can then trigger changes in the titles set. MCO and INP are context setters. Initialisation presents a special problem: as SUs initialise they request constants and require immediate access to them. However, access requires a context to be set that would not normally be defined until processing of the first event begins i.e. during execution. So context setters have a second role: during initialisation they are called first to define an initial context. Other SUs then initialise within this context. MCO provides a context by looking to see what the start date and data type are and INP does it by sneaking a look at the first event to be processed.