@marchick,
Just an FYI, MCUSA has the proposed standard for Birchen Marans (aka Silver Birchen) posted on its website. This standard proposes the following for both the Male and Female as it pertains to lacing:
1. Head: Silvery white
2. Neck - Hackle: lustrous black laced with silvery white
3. Neck - Front of Neck: lustrous black, evenly and finely laced with silver, free from white shafting
4. Upper Breast: lustrous black laced with silvery white free from white shafting
5. Lower Breast: Dull Black
This proposed standard is for USA so there may be differences for the SBM for other countries. I’m not sure if there is a French SOP for SBM as this Variety I believe is not an accepted variety in France.
Take Care,
Keith