...the world's largest and most comprehensive dictionary of acronyms, abbreviations, and initialisms...contains more than 4 million acronyms and abbreviations...
It covers several categories including Information Technology, Military & Government, Business & Finance, Science & Medicine, Organizations & Schools, and even Slang & Pop Culture. This is definitely worth a bookmark.
But that's not all! "You can also search for more than 850,000 US and Canadian postal codes."
They have so much there, I'm wondering if they're able to squeeze in anything else there.