Rules that define how data should be structured, validated, and maintained to ensure it is useful, accurate, and consistent within an organization. These rules are aligned with data quality dimensions and can be enforced through systems, software, or templates. Examples include defining value formats, verifying completeness, ensuring data falls within predefined ranges, maintaining consistency between attributes, and confirming data accuracy. Rules can also involve checks for uniqueness, timeliness, and mapping data between different systems or standards to ensure alignment and quality across processes.