Well, if it’s a new insider, which is indicative of a merger, then that would fall under form 3 and these are the form 3 rules.
What's a Form 3? When a person becomes an insider (for example, when they are hired as an officer or director), they must file a Form 3 to initially disclose his or her ownership of the company's securities. Form 3 must be filed within 10 days after the person becomes an insider.