Screen print of the Revenue Officer Lookup Tool.Line 1: Search By and then a combo box.Line 2: Enter the first 6 digits of the 8 digit assignment number and then a text field entry box.Line 3: Search button.Line 4: (Updated 9/26/2016)Line 5: Note to Accounts Management Users: Used this tool ONLY IF the taxpayer’s account is in Status 26 and assigned to an RO. If there is no TSIGN or the TSIGN ends in 00, the case is NOT assigned to a RO and you should follow the instructions in IRM