Product Keys, Updates and Support
Product keys are an update/support entitlement mechanism for products that use them; they are not a replacement for the software license.
A product key is not the software license
Where a TTB product uses a product key, the key identifies an update or support entitlement. It does not rewrite the legal license that applies to the source code. Joomla extensions submitted to the JED must remain functional without a commercial key when JED rules require that behavior.
Some products do not use a key
Not every store product needs the same update mechanism. The product page and administrator interface are the authoritative source for whether a key is available or optional. Do not copy a key from one product into another product's settings.
Keep keys private
A product key should be treated like an account credential. Do not publish it in screenshots, forum posts, source repositories or public issue reports. If a key must be reset or rebound, use the account or support workflow instead of sharing it publicly.
Update access can expire while installed software keeps working
For products with a limited update period, expiry affects access to protected future package versions or support services. It should not silently disable the core functionality of an already-installed JED-compatible Joomla extension.