Grothendieck calls a "discretification" of a profinite group $\widehat G$, a discrete group $G$ whose profinite completion is isomorphic to $\widehat G$. Does Grothendieck also define a notion of the "discretification" of a functor to profinite groups, and particulary that of the algebraic fundamental group functor? The automorphisms of the geometric point act on the discretifications of the fundamental group functor; and thus one can ask: >are all discretifications of the the algebraic fundamental group *functor* related by automorphisms of the geometric point? To simplify the question, one may abelianise the functor and/or restrict it to a full subcategory of schemes $X\longrightarrow S$, $S=\mathrm{Spec}\ k$ a number field or $k=K$. Here is the same question with some more notation and detail. Please excuse my poor notation: I am not very familiar with the language of schemes. Say a functor $F$ to finitely generated Abelian groups is a _discretification_ of a functor $F'$ to profinite groups iff for every $X$, $F(X)$ is a discretification of $F'(X)$. Equivalently, one is given an equivalence $\widehat F \Rightarrow F'$ (where $\widehat F(X)=\widehat{F(X)}$ is the profinite completion of $F(X)$.) The algebraic fundamental group is, or at least defines, a functor $\pi_1^{alg}: \mathrm{Spec}\ K\text{\Schemes} \longrightarrow \text{ProfiniteGroups}$ from the category $\mathrm{Spec}\ K\text{\Schemes}= \mathrm{Mor} (\mathrm{Spec}\ K, \text{\Schemes})$ of Schemes cosliced over a geometric point $\mathrm{Spec}\ K$. There is a canonical $\mathrm{Aut}(K/\mathbb{Q})$ action on $\mathrm{Spec}\ K\text{\Schemes}$ which extends to an action on the discretifications of this functor. Did Grothendicek conjecture anything about this action? Is there a better way to state this question? E.g. using the fact that for K the field of algebraic numbers $\mathrm{Aut}(K/\mathbb{Q})=\pi_1^{alg}(\mathrm{Spec}\ \mathbb{Q}, \mathrm{Spec}\ K)$. One can modify the question by replacing the category of Schemes by a subcategory of Schemes over $\mathrm{Spec}\ k$ or some other scheme, and then considering double cosets of $\mathrm{Aut}(K/\mathbb{Q})$ and $\mathrm{Aut}(k/\mathbb{Q})$ action; as an example, one may consider the full subcategory of etale covers of direct products of moduli spaces of curves.... Perhaps I should also add that probably I can prove some very partial positive results, for some very small and "abelian" subcategories of Schemes. That's the motivation for the question.