Constant MR_UPDATE_NEW_LABEL 

pub const MR_UPDATE_NEW_LABEL: u8 = _; // 15u8

Unique label computed as 1 plus the full chiplet selector with the bits reversed. selector = [0 | 1, 1, 1], flag = rev(selector) + 1 = [1, 1, 1 | 0] + 1 = 15