I won't use the MsgBox there because, well, this is one tiny combobox on an entire userform. If every box had a MsgBox, the user would be clicking MsgBoxes all day I've put a ControlTipText for each of the boxes so mouse over will show what the box is for.

Also, the Unload Me will cause the Userform to close as soon as it opens in this process since this is the UserForm_Initialize setup. This is just setting up the form. If the user has already set the prefix previously, then it should show it as set, if it isn't set, then it should show it as unset, but in both instances there should be the option to choose from the list as well.

What exactly does the RTrim do for the process?

Sorry if I sound obtuse, I'm still learning and am coming at VBA a little backwards and with no official knowhow.