See here for a posting by Nathaniel Lalone of Katten Muchin Rosenman LLP on the Lexology web site referring to a call by the FIA for a delay to the start of the commodity derivatives regime under MiFID II. The post refers to an article on the Risk.Net web site which can be found here (pay wall).

The post refers to the fact that data from 2015, 2016 and 2017 is required in order to calculate the results of the Ancillary Activity test. This means that in order to make an exemption filing by 3rd January 2018, as alluded to in the relevant FCA documentation (see here), it is necessary to make inferences.

There are still many questions outstanding on both RTS 20 (Ancillary Activity) and RTS 21 (position limits) which have not yet been addressed by the relevant Q+A document (see here).