; and (B) may not put the interests of the brokerage ahead of those of the brokerage customers. (2) Best execution duty A buy-side brokerage or sell-side brokerage shall seek the most favorable terms reasonably available under the circumstances for each order transaction of the brokerage customer. (3) Transparency requirements (A) In general Upon written request from a brokerage customer, a buy-side brokerage or sell-side brokerage shall supply to the brokerage customer, within a reasonable time, information sufficient to permit the brokerage customer to verify compliance of the brokerage with the obligations under paragraphs (1) and (2). (B) Contents The information described in subparagraph (A) shall include, if requested and to the extent such information is collected by the brokerage in the ordinary course of business— (i) in the case of a sell-side brokerage providing information to a sell-side brokerage customer— (I) a unique and persistent identifier that identifies each unique digital advertising space for sale; (II) for each identifier described in subclause (I), all bids received, and, for each bid received, the bid submitted to the digital advertising exchange on behalf of the buy-side brokerage customer, the winning price, the uniform resource locator or other property identifier at the lowest level of granularity, the identity of the digital advertising exchange or other digital advertising venue returning the bid, date, time that the bid response was received in microseconds or a lower level of granularity, web domain associated with the advertising creative, the advertising creative size and format, and whether the bid won the impression of the seller; (III) the nature of any data collected or derived from the brokerage customer or any user or customer of the brokerage customer, and the ways in which the data is used by the sell-side brokerage; (IV) the order or bid routing practices or processes, including any material exceptions to the standard practice of the brokerage