Trade secret protection is unusual among intellectual property rights: there is no registration, it can last indefinitely, and it is lost the moment the information stops being secret.
What qualifies. Information that derives independent economic value from not being generally known or readily ascertainable, and that is the subject of reasonable efforts to maintain its secrecy. Customer lists, pricing models, formulations, processes and source code commonly qualify; general skill and knowledge an employee acquires does not.
Reasonable efforts is where cases are lost. Courts look for confidentiality agreements, access restricted to those who need it, marking, exit interviews, password controls, and physical security. A company that treats information as freely available internally and then calls it a trade secret in litigation usually fails at this element.
Misappropriation means acquisition by improper means, or disclosure or use by someone who acquired it under a duty of confidence. Independent development and reverse engineering are lawful.
Practical guidance. Identify what the actual secrets are before there is a dispute — litigation requires the claimant to describe them with particularity, and a party who cannot do so quickly is in difficulty. Keep the access logs. And handle departures consistently: the exit process that recovers devices and reminds people of obligations is also the evidence that reasonable efforts were made.