Product ID

Product ID is an ID or SKU of the purchased product. The ISV endpoint
should be aware of this ID/SKU in order to distinguish between various
products (if multiple products are offered).

Examples:

• Bronze
• Silver
• Gold

Upgrade Model

If there are multiple products offered using the same ISV endpoint, then
it’s necessary to define which products can be upgraded and the
corresponding upgrade path.

Examples:

• Bronze -> Silver
• Bronze -> Gold
• Silver -> Gold

Please note that it’s not permitted to have circular dependencies in the
upgrade path. The only permitted direction of upgrades is upward (from
the “lowest” option to the “highest” one). Examples of circular
dependencies:

• Bronze -> Silver, Silver -> Bronze
• Bronze -> Silver, Silver -> Gold, Gold ->
  Bronze

NFR (Not For Resale) Product IDs

Each license key in KA can be marked as NFR (Not For Resale). This means
that such license key is not intended for production use and might be
used for testing or development purposes. Also, such license key is not
a subject for invoicing and billing, and, therefore, should not be
counted in Plesk and ISV mutual settlements.

Only few members of Plesk staff can mark licenses as NFR in KA. So there
is no fear that this can be used in uncontrolled way or in large
quantity. However, this is still a standard facility that should be
supported by the ISV endpoint just to make sure that ISV has an ability
to track NFR licenses on their side independently from Plesk.

KA signals about NFR license by adding “NFR-” prefix to Product ID.
Examples:

• NFR-Bronze
• NFR-Silver
• NFR-Gold

Please note, that the ISV endpoint should not only support straight
product IDs, their NFR counterparts, and upgrades within each of these
two groups; it also should support upgrades between these groups.
Examples:

• Bronze -> NFR-Bronze
• Bronze -> NFR-Silver
• Bronze -> NFR-Gold
• Silver -> NFR-Silver
• Silver -> NFR-Gold
• Gold -> NFR-Gold