SEC Form CB is also referred to as the Tender Offer/Rights Offering Notification Form. This means that SEC Form CB is a filing that is mandated when an entity is dealing with special tender offers, business combinations, or rights offerings with a foreign private issuer that has less than 10% of its securities under a US entity submitted to the Securities and Exchange Commission. SEC Form CB is also used as a report for cross-border transactions to be submitted by both the domestic and foreign entity involved in the transaction.