The attached screens show that a role has ALL access to history lines. Despite that fact, the user assigned that role cannot delete any lines from the history file. Obviously we don't normally want users deleting history lines but if they put one in by mistake, they need to be able to delete it. Why would the user not be able to delete a line if I've given them delete capabilities?
I tested it out and it doesn't work for em either. If I have the user manually create a history line, he can delete it. If it is a history line that is created automatically by creating the service call he can't. That might be by design though. If you are creating a service call an accidentally enter something in wrong, you just remove it. If you've already saved it, then just edit it and it will update the history line. No harm , no foul.