A view overlay is a copy of a view. Creating a view overlay enables you to modify the form layout and the display properties of the fields that are added to the view overlay.
To modify the layout of a field, you must add the field to the view overlay. Then, you can alter the field's layout and display properties. If a patch or upgrade modifies the layout information for the field, your alterations are preserved.
The layout of fields that are not added to the view overlay is inherited from the origin view. If a patch or upgrade modifies layout information for those fields, the new field layout appears on the view overlay. Similarly, if new fields are added to the origin view through a patch or upgrade, these fields are visible in the view overlay with the same layout and display properties that they have in the origin view.
When you open a form, BMC Remedy Developer Studio typically fixes corrupt display properties (such as incorrect Z-order, missing menus, and missing labels). In Best Practice Customization mode, however, such errors in origin views are not fixed. Instead, Developer Studio displays a message saying that the view overlay is required. To fix the corrupt display properties, add the field to the view overlay.
At run time, a BMC Remedy AR System application uses the fields added to the view overlay instead of the original fields.
During an upgrade, the display properties of the fields added to the view overlay are protected from changes that the installer makes. The fields that are not added to the view overlay inherit the base properties during upgrade.
For more information about moving your existing customization when you upgrade the BMC Remedy AR System server, see in BMC Remedy ITSM Deployment online documentation.