► closely controlled/guarded/monitored etc
Political activity is closely controlled. ► a closely-guarded secret
Details of the program are a closely-guarded secret. ► jealously guarded
a jealously guarded secret ► cautious/guarded optimism (=the belief that a future situation will be good or better than before, although you cannot be not sure)· The U.N. sees cause for cautious optimism in what has been achieved so far.· He expressed guarded optimism about the company's future.
► a closely-guarded/well-kept secret (=a secret that few people are allowed to know)· The recipe is a closely-guarded secret.