I wanted to know if it's allowed to say "Nat Geo" here or ever.
I have often used Nat Geo to refer to the magazine although Nat Geo usually is used to refer to the TV channel. I've also used NGM for the magazine, NGC for the channel, and NGS for the Society, Cathy Hunter runs this site and, unless you are vulgar or offensive, you can say pretty much anything you want.
Exactly so! Thanks, Tom.