The 81st Constitutional Amendment Act, 2000 inserted clause (4B) into Article 16 to constitutionally protect the carry-forward of unfilled reserved vacancies. This was enacted in response to judicial decisions that had questioned the validity of accumulating backlog vacancies beyond the 50% ceiling.

1. 1 Pick up Constitution of India.
2. 2 Go to Article 16 (Equality of opportunity in public employment).
3. 3 Find clause (4B).
4. 4 Look for a marginal note like '[Ins. by Constitution (81st Amdt.) Act, 2000]'.
5. 5 If your edition has it → answer found. If not → you need pre-exam memorization.

The text reads: Article 16(4B): Nothing in this article shall prevent the State from considering any unfilled vacancies of a year which are reserved... as a separate class of vacancies to be filled up in any succeeding year or years.