European Commission options elaborated (EC release of 21 November 2013) due to legislative delays and the lack of possibility to apply backloading in 2013 are available here.
They are rather simple, they consist in:
1) backloading as of 2014 on the basis of the initial profile, meaning the postponement of backloaded volumes from previously scheduled years 2013, 2014 and 2015 in identical proportions into the subsequent years 2014, 2015 and 2016 (option 1);
2) the distribution of the 2013 backloaded volumes into years 2014 and 2015 - effecting (as opposite to the option 1) in no backloaded volumes in 2016 (option 2).
Under option 1 a sub-option has been differentiated which consists in adding a provision in the following wording:
"Where in 2014 the volume of reduction set out in Annex II cannot be spread over a period of more than [x] months it shall be decreased by [xxx] million allowances. In that case, the volumes of reduction for 2015 and 2016 shall be adjusted in equal instalments accordingly."