Constant MR_UPDATE_OLD_LABEL 

pub const MR_UPDATE_OLD_LABEL: u8 = _; // 7u8

Unique label computed as 1 plus the full chiplet selector with the bits reversed. selector = [0 | 1, 1, 0], flag = rev(selector) + 1 = [0, 1, 1 | 0] + 1 = 7