5. Where charges are made by the public sector bodies referred to in point (b) of paragraph 2, the total income from supplying and allowing the re-use of documents over the appropriate accounting period shall not exceed the cost of collection, production, reproduction, dissemination, data storage, preservation and rights clearance and, where applicable, the anonymisation of personal data and measures taken to protect commercially confidential information, together with a reasonable return on investment.
Charges shall be calculated in accordance with the accounting principles applicable to the public sector bodies involved.