Azure, a pale checky sable and argent.
Christophe was introduced to me through the East Kingdom’s “Ask a Herald” service. He already had a design in mind that was a good match for his 12th Century Sicilian Norman Crusader persona.
However, I soon discovered that, although visually distinct, it conflicted with the populace badge of the Shire of Caer Adamant, azure, a pale vert fimbriated Or, as the College of Arms does not consider fimbriation when calculating heraldic difference.
I contacted the shire’s herald, Don Simeon ben Iuçef de Alcaçar, and through him reached their seneschal, Baron Adolphus Benner, who consulted the local populace and officers and granted Christophe the necessary “permission to conflict” that would allow his arms to be registered.
[Update, Dec 2017: This device was accepted for registration.]