  For a space $X$ let $\mathcal{K}(X)$ be the set of compact subsets of $X$
ordered by inclusion. A map $\phi:\mathcal{K}(X) \to \mathcal{K}(Y)$ is a
relative Tukey quotient if it carries compact covers to compact covers. When
there is such a Tukey quotient write $(X,\mathcal{K}(X)) \ge_T
(Y,\mathcal{K}(Y))$, and write $(X,\mathcal{K}(X)) =_T (Y,\mathcal{K}(Y))$ if
$(X,\mathcal{K}(X)) \ge_T (Y,\mathcal{K}(Y))$ and vice versa.
  We investigate the initial structure of pairs $(X,\mathcal{K}(X))$ under the
relative Tukey order, focusing on the case of separable metrizable spaces.
Connections are made to Menger spaces.
  Applications are given demonstrating the diversity of free topological
groups, and related free objects, over separable metrizable spaces. It is shown
a topological group $G$ has the countable chain condition if it is either
$\sigma$-pseudocompact or for some separable metrizable $M$, we have
$\mathcal{K}(M) \ge_T (G,\mathcal{K}(G))$.
