I thought I'd post the image that Hermano Juan Carlos found in the 1901 Verney-Carron catalog in case it was lost from the image hosting site.
It, and the 1900 Manufacture Française d'Armes de St Etienne catalog would confirm that there was a Poudre R, which was discontinued prior to the 1914 Verney-Carron catalog.
After 1914, only Poudre T was used by the proof house for Nitro proof.
And the image confirms that only Poudre T was smokeless; the others were considered semi-smokeless.

The French equivalent to Nitro Powder is "Poudre Pyroxylée"

[Linked Image from photos.smugmug.com]

BTW: The (same) gunner in the first 4 images has a fairly upright head position; the 5th is crawling the stock and looks to have his thumb touching his nose

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