Product Media Rail 1.0.0 uses schema version 1.

The module creates no module-specific tables. Its interaction settings and schema
version are stored through ModuleManager's existing sys_variable settings service
under the product-media-rail.* prefix.

No rail item, image, image URL, link, product record, customer record, or visitor
data is copied into ModuleManager storage. All rail content is rendered and owned
by the host website or shopping cart.