has special ranges of field IDs. Numbers 1-99 are reserved for core fields. Numbers 100-536868911 are reserved for registered fields. The following table lists reserved field ranges that forms and applications use in .
Important
In the Best Practice Customization mode, a warning is displayed when you create or copy fields in the BMC reserved range on an overlay form. This warning states that creating or copying fields might cause a failure in future application upgrades, if the created field conflicts with a similar field introduced during an upgrade. However, this warning is not displayed when you create or copy fields in the BMC reserved range on a custom form. In the Base Development mode, a warning is displayed when you create fields using the field ranges that are outside the BMC reserved range on a base or overlaid form.