The best reason for writing an information security policy is to support information security governance. Information security governance is the process or the framework of establishing and enforcing the policies and standards for the protection and the management of the information and the systems within an organization, as well as for overseeing and evaluating the performance and the effectiveness of the information security program and the information security controls. Information security governance can provide some benefits for security, such as enhancing the visibility and the accountability of the information security program and the information security controls, preventing or detecting any unauthorized or improper activities or changes, and supporting the audit and the compliance activities. Information security governance can involve various elements and roles, such as:

Information security strategy, which is the plan or the direction that defines and describes the objectives, scope, principles, and priorities of the information security program and the information security controls, as well as the alignment and the integration of the information security program and the information security controls with the business goals and the risk appetite of the organization.

Information security policy, which is the document or the statement that defines and describes the rules and the requirements for the protection and the management of the information and the systems within the organization, as well as the roles and the responsibilities of the information security stakeholders, such as the management, the staff, the customers, or the partners.

Information security standards, which are the documents or the specifications that define and describe the mandatory or the minimum criteria or the guidelines for the implementation and the operation of the information security program and the information security controls, as well as the alignment and the compliance of the information security program and the information security controls with the industry regulations or the best practices.

Information security procedures, which are the documents or the instructions that define and describe the specific tasks or the steps for the execution and the maintenance of the information security program and the information security controls, as well as the monitoring and the reporting of the performance and the effectiveness of the information security program and the information security controls.

Information security roles, which are the functions or the positions that are responsible for the design, the implementation, the operation, the evaluation, or the improvement of the information security program and the information security controls, such as the information security manager, the information security officer, the information security analyst, or the information security auditor.

Writing an information security policy is the best reason for writing an information security policy, as it is the foundation and the core of the information security governance process or framework, and it provides the guidance and the direction for the information security program and the information security controls, as well as for the information security stakeholders. Writing an information security policy can involve various tasks or duties, such as:

Defining and documenting the purpose, scope, objectives, and principles of the information security policy, and ensuring that they are consistent and aligned with the information security strategy and the business goals of the organization.

Defining and documenting the rules and the requirements of the information security policy, and ensuring that they are clear, concise, comprehensive, and relevant to the information and the systems that are being protected and managed by the organization.

Defining and documenting the roles and the responsibilities of the information security policy, and ensuring that they are assigned and communicated to the information security stakeholders, such as the management, the staff, the customers, or the partners, and that they are acknowledged and accepted by the information security stakeholders.

Reviewing and updating the information security policy, and ensuring that it is current and valid, and that it reflects and addresses any changes or issues that may affect the information security program and the information security controls, or the information and the systems that are being protected and managed by the organization.

To reduce the number of audit findings, to deter attackers, and to implement effective information security controls are not the best reasons for writing an information security policy, although they may be related or possible outcomes or benefits of writing an information security policy. To reduce the number of audit findings is an outcome or a benefit of writing an information security policy, as it implies that the information security policy has helped to improve the performance and the effectiveness of the information security program and the information security controls, as well as to comply with the industry regulations or the best practices, and that the information security policy has supported the audit and the compliance activities, by providing the evidence or the data that can validate or verify the information security program and the information security controls. However, to reduce the number of audit findings is not the best reason for writing an information security policy, as it is not the primary or the most important purpose or objective of writing an information security policy, and it may not be true or applicable for all information security policies.