Logbooks to retain names from dropdown lists after they leave

When you use a logbook and a drop down list to detail who has logged the information or raised the issue, once that person leaves their name disappears from the logbook record.

For example, where a manager has made a note about a performance issue, they firstly choose their name from the list as the logger. That manager has now left so all historic records that have been done by them no longer have their name attached.

A work around is to use a text box but in that case why have the drop down list at all as it is only relevant to active employees.

Should it be necessary to go back to look at notes made in relation to a claim etc the name of the individual who made the log is no longer available