Quality control cost accounting standard sets rules for measurement, allocation, presentation, and disclosure in cost statements. Cost Accounting Standard CAS-21 governs the measurement, assignment, presentation and disclosure of quality control cost in cost statements. It defines quality control cost and related terms, including defectives, rework, rejects, scrap, waste and spoilage, and requires in-house and externally procured quality control resources to be measured on specified cost bases. The standard excludes finance costs, imputed costs, abnormal portions, penalties and damages, and requires allocation to cost objects by traceability or benefits received, with material costs presented separately and disclosed in the cost statement.