Codes of practice approved under section 12 of Cap. 486 change how a request plays out by sector.
Banking and consumer credit data is governed by the Code of Practice on Consumer Credit Data. When a lender has considered a credit report, the Code expects it to tell you so and to explain how to contact the credit reference agency that supplied it. That agency is a separate data user, so it receives its own request. The bank itself keeps call recordings and relationship manager notes. Naming them in the request is the difference between a full answer and a one-page statement.
Employment records fall under the Code of Practice on Human Resource Management, which generally limits retention of a former employee's data to seven years after the employment ends and of an unsuccessful applicant's data to two years. Employers often rely on section 55 to withhold evaluative material while a promotion or disciplinary process is running. That exemption ends once the decision is made. Opinions about you recorded in an appraisal are your personal data, even when the appraiser's own name is redacted.
Healthcare providers hold the most sensitive data in the system. Section 59 allows a data user to withhold health data where disclosure would be likely to cause serious harm to the physical or mental health of the data subject or another person. A hospital cannot rely on it simply because the notes are unflattering. A copy of your clinical data is not the same as a medical report written for you, which is a separate service outside the Ordinance.
Government bureaux and departments each designate a data protection officer and publish the contact address in their privacy policy statement. Many departments state expressly that a request not made on Form OPS003 may be refused under section 20(3)(e), so the specified form matters most here. Naming the division that holds your file shortens the search considerably.