Exploring symbols

I was thinking about the first week of Foundations of Library & Information Science, where we explored the Ampersand symbol, its meaning, origin, and definition., as we discussed the need to look up symbols, terms, and concepts for library patrons even if we know the answer. On one of the listservs I frequent, there is a posting for an article in the current New Yorker (Sept 6, 2013) about Hashtags, Manicules, and more. The article written by Keith Houston is entitled "Ancient Roots of Punctuation" http://www.newyorker.com/online/blogs/books/2013/09/origins-of-hashtag-manicule-diple-pilcrow-ampersand-explained.html
 The article explores the origins of various symbols, including the number sign which can be used as an abbreviation for Pound, or lb. As with Ampersand, I was amazed that I use this symbol frequently and had no idea of its origins. If you are intrigued with the article, you might look at his book Shady Characters: The Secret Life of Punctuation, Symbols, and Other Typographical Marks . 

What did you learn today?