The phrase "secret designs" is correct and usable in written English.
You might use this phrase to describe someone's plans that they don't want to reveal openly. For example: "John has been working on secret designs for a new invention."
And yet rumour had it that Oakey harboured secret designs on Sulley.
And then there is HAL, the rogue computer whose affectless red eye reflects back what it sees while, behind it, his mind whirrs with dark and secret designs.
Nevertheless, Dr. Sailor said he believed that the military might be interested in the technology for protecting the secret designs of specialized chips in nuclear weapons, surveillance equipment and other devices.
Officials detailed how Dr. Khan had presided over a network that smuggled nuclear hardware on chartered planes, had shared secret designs for the centrifuges that produce the enriched uranium necessary to develop a nuclear weapon, and had given personal briefings to Iranian, Libyan and North Korean scientists in covert meetings abroad.
NIGHT VISIONS: The Secret Designs of Moths, by Joseph Scheer; Prestel; $45.
While Westinghouse was negotiating a deal with a Chinese state-owned firm to build nuclear power plants, Unit 61398 stole secret designs for plant components, he said.
Another was the stealth with which Cimino seemed to be following a secret design.
Can this be described as secret design that is embedded in fabric and construction but not immediately visible?
Finally, after four years, the investigation ended with American intelligence agencies no closer to knowing how China obtained the secret design of the nuclear warhead.
Soyez attributes his success to the fact that the company built its own machines based on American technology (still a secret design) and to "luck".
For all we know they might even be cooking up a hoverboard in their secret design lab – one that doesn't explode and only comes in white.
