The Official Secrets Acts ( note the plural) are incorporated into U.K. legislation. "Signing " them is just an admission that you are aware of the implications, since you are ( if a U.K. citizen) subject to them in any event. Not having signed them is no defence in the event of their violation.
Whilst we are on the topic of such legislation, the "right of the press not to disclose it's sources" is another myth that has no standing in law.
Last edited by Haraka; 12th Jun 2015 at 05:27.