[deanmen]

Lying always being unethical is actually a relatively standard idea in classical ethical theories e.g. Summa Theologica, Question 110, Article 3. However, the statement that the class involves "no coding" could be considered truthful in the social context or as part of a use of mental reservation.

[Thiez]

Lying can be perfectly okay under consequentialism, which also goes way back. Personally I'm not very convinced of ethical theories where lying is unethical in all circumstances (sorry Kant), and I suspect I'm not the only one. Stating that there exists an ethical theory that supports your point just isn't very convincing for people who don't subscribe to that particular theory.