When exporting a .csv (with all fields) from an advanced search the work log is included, which contains a timestamp, the user who logged the work, and the amount of seconds logged.
My issue is, that some users appear as an id and others appear as initials in the .csv:


I assume the ID is shown, when the user has no initials specified, so how do I add initials to users, so that users appear as initials in the log work fields of future exports?