Use Caution When Editing a Custom Field

Settings that cannot be changed once the custom field is created

Field type

Use caution when changing these settings

WARNING! Changing these settings may result in saved data becoming inaccessible.

Controlled by Policy
Apply to
Multi-select to single select
Not Required to Required
Store the Displayed Name
Display Name
Stored Name

EXAMPLE If you have a string-based custom field that currently contains Social Security Numbers (SSNs) and decide a year later that you want to change that field to email addresses, the SSN data will no longer validate properly. Your certificate manager will get an error message if he or she tries to save the object using an SSN value. There is a potential for mismatched data due to the different validation strings.
In this case you may want to consider creating a new custom field for email addresses.