It is clear (SE)^2 is about Space Exploration. Being a relatively new site here on SE, some questions may have been posted on other SE sites. Amongst others, Where is our demarcation line between Space Exploration and Physics? is a related question, albeit not identical to the intent here.
If a question posted here on (SE)^2 was covered on another SE site, is it acceptable to link the two questions across forums? This is not about a cross-post, merely a link to a question on another SE site.
I can't think of any objectionable reasons for reusing Stack Exchange resources, where appropriate. If crediting the original author of the quoted / linked to contents is in order, then by all means, we should try to give credit where credit is due by at least mentioning it in the references, but otherwise we're all working towards the same goal (promoting our own Stack Exchange websites), so there ought not be much of unhealthy insider competition going on, or if it is, should be dismissed on grounds of the greater good - benefit for the whole Stack Exchange community.
Look at me, talking like some presidential candidate LOL!! And I like your SE2 shorthand for our website, but we already have one that I believe @ManishEarth coined first: SEx.SE. It doesn't get sexier than that, and not only due to who coined it (well, he does have the moderator diamond, which is a superlative on its own merit, and not for us puny mortals to argue with). :)
