documentclass{memoir}
usepackage{amsmath}
usepackage{unicode-math}
usepackage[noabbrev]{cleveref}

begin{document}

begin{align*}
    A
        &=B         \
        &=BCD       \
        &=B
end{align*}

begin{align}
    A
        &=B         label{eq:1}\
        &=B         notag\
    A
        &=BCD       label{eq:2}\
        &=B         label{eq:3}tag{foo}
end{align}

References: eqref{eq:1}, cref{eq:2}, cref{eq:2,eq:1}, cref{eq:2,eq:1,eq:3}.

end{document}