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This is a terminology question about a class of log varieties.

Given an fs (fine and saturated) log variety $(X, M)$ (for $M$ the defining sheaf of monoids), any geometric point $x\in X$ has a finitely-generated saturated (a.k.a. normal) monoid $\overline{M}_x=M_x/\mathcal{O}_x^\times,$ which is in some sense "responsible" for the log structure at $x$.

I want to give a name to the subcategory of log varieties for which $\overline{M}_x$ is free, i.e., isomorhpic to $\mathbb{N}^k$ at every point (here $k$ can depend on the point). If $(X,M)$ is a smooth log variety, this condition is equivalent (at least in characteristic $0$) to the defining divisor of $M$ being normal crossings. In the past, I've called varieties "of normal crossings type", but I'm not so happy with the name, since it suggests smoothness whereas many non-smooth log varieties (such as the log variety on a point with $\bar{M} = \mathbb{N}^k$) have this property.

Other names I've considered are "regular" (but "regular monoid" means something else) and "cartesian" (but that conflicts with terms in algebraic geomtery and category theory). Is there a standard name for such varieties?

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    $\begingroup$ I've seen such log structures called "locally free" in the literature, for example Definition 1.5 of Olsson's "On (log) twisted curves", so I've used "locally free log scheme" for such log schemes. $\endgroup$ Commented Oct 25, 2022 at 18:11
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    $\begingroup$ @DoriBejleri Thanks! I think I've looked at that paper, but hadn't rememberd the definition. I thought about that one as well but was worried that notation is still a little ambiguous. I'm glad it's been used. $\endgroup$ Commented Oct 25, 2022 at 18:19

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