ACL_BRAND_UNKNOWN
if (brand1 == ACL_BRAND_UNKNOWN || brand2 == ACL_BRAND_UNKNOWN)
case ACL_BRAND_UNKNOWN:
if (_acl_brand(acl) == ACL_BRAND_UNKNOWN)
if (_acl_brand(acl) == ACL_BRAND_UNKNOWN) {
acl->ats_brand = ACL_BRAND_UNKNOWN;
assert(_acl_brand(a) != ACL_BRAND_UNKNOWN);
assert(_acl_brand(b) != ACL_BRAND_UNKNOWN);