On 30 November, the Inclusive Framework on BEPS has released additional guidance for tax administrations and MNE Groups on the implementation of Country-by-Country Reporting (BEPS Action 13).
http://www.oecd.org/tax/beps/guidance-on-country-by-country-reporting-beps-action-13.htm
The additional guidance addresses a number of specific issues: how to report amounts taken from financial statements prepared using fair value accounting; how to treat a negative figure for accumulated earnings in Table 1; how to treat mergers/acquisitions/de-mergers; how to treat short accounting periods; and the definition of total consolidated group revenue.