Using as true any such declaration known to be false is dealt under

Section 200 of the Indian Penal Code (IPC) specifically deals with the offence of using as true any such declaration which is known to be false. This section applies when a person makes a declaration or statement and knowingly uses it as if it were true, despite being aware that it is false. Such conduct is punishable under IPC because it amounts to deliberate misrepresentation and dishonesty in legal or official contexts.

Section 199: Relates to making a false statement in a declaration which is by law receivable as evidence.

Section 200: Relates to using such a false declaration as true, knowing it to be false.

Section 201: Deals with causing disappearance of evidence of an offence or giving false information to screen an offender.

Section 202: Relates to intentional omission to give information of an offence by a person legally bound to inform.

Therefore, the correct section under IPC that deals with using as true any such declaration known to be false is Section 200.