I'm new here. Yesterday I posted a couple of electrical questions in DIY. Later in the day I discovered, by accident when searching for some related material, that my questions also appeared on stucksolver.com and solveforum.com. They're visible on a few other sites as well but the others appear to be connected to SE, or at least they show the SE logo when loaded (e.g. superuser.com, askubuntu.com). stucksolver and solveforum do not appear related to SE. There are posts there from other SE sites, not just DIY.
Is all this expected behavior? Are SE posts supposed to show up elsewhere like this?

