False Declaration

If you have a criminal conviction and do not declare it in, say, a job application, then you are knowingly using false information to benefit yourself. In Hong Kong laws you would be liable for the offence of "Using a False Instrument" -
Cap. 200 CRIMES ORDINANCE SECT 73 - The offence of using a false instrument:

A person who uses an instrument which is, and which he knows or believes to be, false, with the intention of inducing somebody to accept it as genuine, and by reason of so accepting it to do or not to do some act to his own or any other person's prejudice, commits an offence and is liable on conviction on indictment to imprisonment for 14 years.