There are some documented "lost" technologies developed by the alchemists. Examples include flexible (bendable) glass and methods for coloring metals through (not just surface coloration, as in anodized aluminum).
That information is unknown to the public.
This is unknown to the public
The answer is unknown, and will likely remain unknown until it is released to the public.
The address is unknown to the public.
that question is unknown
his weight is currently unknown to the public
That information is unknown to the public.
Yes, definitely. The author is unknown.
she is unknown to all public she has not said anything,
He has a bull dog. Her name is typically unknown to public.
They aren't a public band and so this is unknown.
It is unknown if "sssniperwolf" has a KIK account. There is not a list of usernames available to the public.