Sir John FRENCH & Sir Douglas HAIG - Rank and Post-nominals on certain dates?

[Skipo]

All,

Very grateful for your expertise. Can anyone please tell me what rank and post-nominals should be ascribed to Sir Douglas Haig on the following dates? They are 9 April 1917, 13 October 1917 and 14 December 1917.

Also, the same question for Sir John French on 21 August 1914.

Very grateful for a definitive answer as I'm not sure how to confirm.

Thanks in advance,

Skip