In fairness to underwriters a reference source previously did not exist. Lunch hours and coffee breaks present excellent opportunity for study and review. Rather, learn to exercise your imagination much the same way an agent does when he records it. Think of letters, or numbers, as interchangeable modules, or components. Then apply logic.
Numbers are really quite basic.
Recently an auto application was returned to me with what was believed to be an incorrect driver's license number. For the record, the application was correct. Done correctly it will match the name on the application. If not, then move on to phase II and guess. If still unsuccessful then, and ONLY then, return the application to the agent so he may venture some guesses before contacting the applicant for clarification.