<sub>(Note: I'm a [UL mod](https://unix.stackexchange.com/users/73/michael-mrozek), so when I say "we" I mean Unix and Linux Stack Exchange)</sub>

If it's a question about Unix and Linux and you don't want it, odds are we do; we're [fairly inclusive](https://unix.stackexchange.com/faq#questions). We have this same overlap problem with other sites, notably Ask Ubuntu, so here's what we do with them:

* Questions about Ubuntu that have no bearing on other distros are migrated from UL to AU
* Questions about Unix or Linux that don't apply to Ubuntu at all are migrated from AU to UL
* All other questions are left where they're posted unless the OP asks us to move them

I generally apply the same logic to other sites, even if we haven't specifically talked about it. So we almost never migrate here (3 times in the last 3 months), because it's rare for someone to ask a sysadmin question that doesn't involve Unix or Linux. Similarly, we don't expect you to migrate Unix/Linux questions to us if they're on-topic here -- you should only migrate a question if SF isn't a good place for it, or the OP changes their mind and wants it somewhere else.

I'll also mention that one thing you shouldn't do (or encourage others to do) is [cross-post](https://unix.stackexchange.com/faq#cross-posting). Sites differ on their tolerance for cross-posting; we usually close a question if we find out it was posted on multiple sites. Either pick a site, or tailor your question for the individual sites you're asking it on -- don't just copy/paste it to all the sites that sound relevant