A more thorough explanation:

Definition: Rights on refers to the entitlement of a cum rights purchaser of stock to receive declared but undistributed rights, such as the right to purchase additional shares at a predetermined price.

Example: If a company declares a rights issue, it means that existing shareholders have the right to purchase additional shares at a discounted price. A cum rights purchaser of stock is entitled to these rights, even if they were not yet distributed at the time of purchase.

Explanation: The example illustrates how a cum rights purchaser of stock is entitled to receive declared but undistributed rights, such as the right to purchase additional shares at a discounted price. This means that even if the rights have not yet been distributed at the time of purchase, the purchaser is still entitled to them.