• Special events that need to be shown on ELH's include
• Abnormal Death events (special use of quit/resume)
• Special checks on effects of death of master (cascade effects)

• Result of the occurrence of an event
• May be non-updating depending on the state of the entity
• Can use Effect qualifiers

• An event can affect two occurrences of an entity in two different ways, depending on their state. E.g. rescheduling of a course run. Causes deletion of existing course run and creation of new one. This is a simultaneous effect on a ELH. The role of the entity when it happens is shown in square brackets.

• A single byte attribute changed every time an entity is updated.
• They appear under leaves on ELH's
• Each leaf has a before end after value, starting at 1 for creation and increasing with new events.
• First and last values are null -/1
• On an iteration the valid previous indicators include the new valid indicator
• If a value is not to be changed it is an asterisk
• Quit and resume sets state value before quit
• They are the last thing to be done to an ELH.
• Why bother ?
• It can be very useful to know the state of an entity from a processing viewpoint. It explains where the entity is in its Life History and also a little of where it has been.

Please see Weaver chapter 11 for example diagrams.