Which of the following is NOT a formally prescribed device available to members of the Indian Parliament under the official Rules of Procedure?

Introduction / Context:
Members of Parliament in India use various procedural devices to raise matters of public importance, seek information from the government and hold the executive accountable. Some of these devices are formally mentioned in the Rules of Procedure and Conduct of Business, while others have evolved by convention and practice. This question asks you to identify which device is not formally written into the rules, even though it is widely used in practice.

Given Data / Assumptions:

Four devices are listed: Zero Hour, Call Attention Notice, half an hour discussion and short duration discussion.
The question asks which one is not formally prescribed in the Rules of Procedure for Parliament.
It is assumed that you know the difference between conventional practices and formally recognised rule based procedures in parliamentary work.

Concept / Approach:
Zero Hour is a term used for the period immediately following Question Hour in Parliament, during which members can raise urgent matters without prior notice under the rules. However, Zero Hour is not mentioned in the official Rules of Procedure; it has evolved as a parliamentary convention. In contrast, Call Attention Notices, half an hour discussions and short duration discussions are formally provided for in the rules, with specified procedures for admission, notice and conduct. The approach is to identify Zero Hour as the conventional device that is not explicitly codified in the rule book.

Step-by-Step Solution:
Step 1: Recall that Zero Hour refers to the time right after Question Hour, usually starting at noon, when members can raise matters of urgent public importance. Step 2: Although Zero Hour is regularly used and recognised in parliamentary practice, it is not mentioned in the original Rules of Procedure. It is thus considered a convention rather than a formal rule based device. Step 3: Call Attention Notice is a formal device under which a member, with the permission of the Speaker or Chairman, can call the attention of a minister to a matter of urgent public importance and seek an authoritative statement. Step 4: Half an hour discussion is another formal device used when a member desires further clarification on a matter already answered during Question Hour, and its procedure is explicitly provided in the rules. Step 5: Short duration discussion, often called two hour discussion, is also a formally recognised device permitting discussion on an urgent matter of public importance without a formal motion being put to vote. Step 6: Since the question asks which device is not formally prescribed, and only Zero Hour fits that description, Zero Hour is the correct answer.

Verification / Alternative check:
Polity textbooks typically explain that Zero Hour is not a rule based provision but a convention that began in the nineteen sixties. They explicitly mention that Call Attention Notice, half an hour discussion and short duration discussion are recognised in the Rules of Procedure of both Houses. This contrast is often highlighted to illustrate how parliamentary practice can go beyond written rules, confirming that Zero Hour is the device not formally prescribed.

Why Other Options Are Wrong:
Call Attention Notice: This is clearly provided for in the rules and allows members to seek ministerial statements on urgent matters. Half an hour discussion: This device is codified and used when members need further clarification on answers given during Question Hour. Short-duration discussion: Also known as two hour discussion, this is formally mentioned in the rules for raising urgent matters of public importance without voting.

Common Pitfalls:
A common confusion arises because Zero Hour is so widely used that many students assume it must be officially codified. Another mistake is to think that all question related devices have the same status. To avoid errors, remember that Zero Hour is the classic example of a parliamentary convention without explicit rule book sanction, whereas the other devices in the options are rule based mechanisms laid down in the official procedures of the Lok Sabha and Rajya Sabha.

Final Answer:
The device that is not formally prescribed in the Rules of Procedure of Parliament is Zero Hour.