1. Operators of trading venues which operate trading systems on a price visibility-time priority shall maintain a record of the priority time stamp for all orders as specified in field 13 of Table 2 of the Annex. The priority time stamp shall be maintained with the same level of accuracy specified by Article 4(1).
2. Operators of trading venues which operate trading systems on a size-time priority basis shall maintain a record of the quantities which determine the priority of orders as specified in field 14 of Table 2 of the Annex as well as the priority time stamp referred to in paragraph 1.
3. Operators of trading venues which use a combination of price-visibility-time priority and size-time priority and display orders on their order book in time priority shall comply with paragraph 1.
4. Operators of trading venues which use a combination of price-visibility-time priority and size-time priority and displays orders on its order book in size-time priority shall comply with paragraph 2.
5. Operators of trading venues shall assign and maintain a sequence number for all events as specified in field 15 of Table 2 of the Annex.