[cm/prv/] with SLH-DSA-SHAKE-256s.
255-bit security level, small variant and simple parameters.
=> SLH-DSA

    prv-slh-dsa-shake-256s {
        {field . {map} len=~}
        {field a {str} =slh-dsa-shake-256s}
        {field v {bin} len=128}
    }