PSL Sub Sector is the classification field identifying priority sector lending sub sector for reporting, underwriting, or workflow routing. It should use controlled master values instead of free text. Define valid values, source, and regulatory or policy relevance. In credit appraisal, it supports identity checks, eligibility validation, regulatory classification, legal due diligence and audit readiness. The field should be supported by documentary evidence and should remain consistent across application data, KYC records and regulatory reporting. For example, correct PSL tagging ensures the bank reports the exposure under the right regulatory category and avoids misclassification. It matters because incorrect classification or missing evidence can create regulatory risk, wrong scheme treatment, audit exceptions or delayed approval. The common caution is to rely on verified documents and current regulatory rules rather than informal borrower declarations or outdated master data.