There is no way to customize those standard Title field options (so that it displays more custom Titles as specific value options listed under this field). However, this field was designed to offer this kind of built-in customization by having the "Custom Title" option serve as an alternative for anyone who might wish to have a more specific title associated with their account in the system. 

The reason why those standard options are relatively generic is because there is a wide variety of types of organizations that use eTapestry, so it would be impractical to display ALL of the various different titles that might be commonly used for one organization's purpose and perhaps not for another organization's purpose. For example, if your organization is a religious organization, then you might have accounts that you'd like to have entered with "Rev." as the Title. That's why that "Custom Title" field is available to you (since it provides you with the opportunity to assign more specialized titles, if desired). If we offered preset options for all potential types of titles that any charitable organization might commonly deal with, then that drop-down list would be excessively long (and would just create unnecessary clutter for other eTapestry clients who might not commonly deal with certain kinds of Titles).