  J.P. Levine introduced a clover link to investigate the indeterminacy of the
Milnor invariants of a link. It is shown that for a clover link, the Milnor
numbers of length at most $2k+1$ are well-defined if those of length at most
$k$ vanish, and that the Milnor numbers of length at least $2k+2$ are not
well-defined if those of length $k+1$ survive. For a clover link $c$ with the
Milnor numbers of length at most $k$ vanishing, we show that the Milnor number
$\mu_c(I)$ for a sequence $I$ is well-defined up to the greatest common devisor
of $\mu_{c}(J)'s$, where $J$ is a subsequence of $I$ obtained by removing at
least $k+1$ indices. Moreover, if $I$ is a non-repeated sequence with length
$2k+2$, the possible range of $\mu_c(I)$ is given explicitly. As an
application, we give an edge-homotopy classification of $4$-clover links.
