When changing a custom field type, which of the following rules apply?

When changing a custom field type, it's important to understand that the appropriate handling of previous values is contingent upon choosing compatible field types. If the new field type is compatible with the existing data (for example, changing a text field to an auto-number field), the previous values can remain intact. This means that, as long as the new type can logically accept the existing data format, the transition will not lead to data loss, and the values currently stored in that field can still be accessed after the change.

The ability to maintain previously recorded values is particularly valuable for data integrity and continuity within the platform, ensuring that historical data is preserved. However, there are certain types of field changes that could lead to data loss if they are not compatible. For example, switching from a picklist to a text area could potentially result in lost data if not handled correctly.

In summary, choosing types properly during a field type change is crucial to ensuring that previous values remain intact, thereby maintaining the integrity and usefulness of the data.