Which of the following is NOT allowed for agreement under the specific schedules of the General Underwriters' Agreement?

In the context of the General Underwriters' Agreement, the option indicating "Bureau leaders only" is not allowed for agreement under the specific schedules. The General Underwriters' Agreement typically focuses on how agreements can be structured among certain types of underwriting parties within the insurance market.

Market leaders and independent brokers play a critical role in forming these agreements, as they represent a collective approach to underwriting within the insurance industry, enabling cooperative decision-making. Bureau leaders, while they hold significant positions in market operations, are not specifically designated under the general framework of agreements set out by the General Underwriters' Agreement. This means that while they may lead a market segment, they do not partake in agreements in the same way that market leaders or independent brokers do.

The nature of underwriting agreements requires a collaborative approach that involves consensus among underwriters, hence "All underwriters jointly" is an accepted method, fostering an environment where shared risks can be managed effectively across a broader community of underwriters, leading to balanced and fair practices.

In summary, the structure of how agreements are formed under the specific schedules of the General Underwriters' Agreement does not include bureau leaders, making that choice correct in identifying what is not allowed in the context of these agreements.