What does "economy of words" mean to me?

The economy of words! Say what you have to say, but use the least amount of words to do so. My audience may decide to skip my ideas or even misunderstand them otherwise.

"Simplicity is the ultimate sophistication" (Leonardo da Vinci)

HT  http://economyofwords.tumblr.com/

What's a "hat tip"?

A "hat tip" during the era when men used to wear hats was an acknowledgment or a non-verbal greeting. It was considered a polite gesture and it extended to  become a means to show respect and accreditation. In the early 2000's hat tip became an acknowledgement to someone (or a website) for bringing something to the blogger’s attention. Hat tip is also, sometimes, abbreviated as h/t or HT" (bloggossary.com). Hat tips also encourage a sense of community by allowing online members/bloggers to mention each other in a positive manner.

HT Blogossary.com; Wisegeek.com