Formal titles, name prefixes, and name suffixes can be recorded on the Naming tab of the Current Person Other Detail dialog (click the … button next to the name fields). These are then used on charts and in narrative reports.
The Civil/Noble Title field is free-form. Examples include "Mayor of London" or "Earl of Derby".
The Name Prefix and Name Suffix fields offer a pre-populated list of common values, but you can also type your own.
Examples of prefixes: "Dr.", "Rev.", "Sir", "Capt.", "Lady".
Examples of suffixes: "MBE", "MD", "Senr.", "Jr."