I saw this answer about MarsGRAM, and when I clicked on the NASA software link to read about it I saw at the bottom of the page a blurb for EarthGRAM 2010, an atmospheric model for Earth with likely all kinds of insight beyond a simple scale heigh or scale height modified by temperature spherical model.
I was happy to see "open-source", as well as the easy-to-read and transcribe "FORTRAN" language.
But at the bottom it says "U.S. Release Only" and I am living overseas.
Question: What does it mean when a software is called open-source for US-release only? What are the rules exactly? Does this refer to the location of download, or of use, or to the citizenship of the person requesting the software?
So far I have not been able to find out what the restrictions really are. I've cycled through a few links but so far without initiating a request for the software, I am not sure how to view the restrictions on eligibility.