Celebrate #NationalPunctuationDay with a Salute to the Octothorpe

National Punctuation Day, celebrated Sept. 24 each year, gives us a chance to have a little nerdy fun or to rant about our pet peeves. Maybe I should I say pet peeve's: making plurals of uncommon words with an apostrophe is one of mine. One of my favorite restaurants had Banana's Foster French Toast for years. Even if I wince at a menu, I can still love the restaurant.

So what the heck is an octothorpe? It's that eight-pointed symbol more commonly known as a number sign, pound sign (another pound sign is £), or hash mark.

The odd name was made up by someone in Bell Labs during the development of the Touch-Tone phone. Obviously, it hasn't caught on, because thousands of automated answering systems advise us to "press the pound key" or enter our PIN, "followed by the pound sign"—and even the most annoying phone tree doesn't mention an "octothorpe." For more on the history of this and other punctuation marks, see Keith Houston, The Ancient Roots of Punctuation, New Yorker (Sept. 6, 2013), or Houston's book, Shady Characters: The Secret Life of Punctuation, Symbols & Other Typographical Marks (2013).


This punctuation mark has a use in legal research. In Westlaw, if you put a # in front of a word, the system will search for the word just as you typed it. This overrides what is usually a convenience: it's handy to have the system search for "labor" when you type "labour," and to look for plurals. But if you ever want to search specifically for "labour" (perhaps in a company name) you can enter #labour.

If you venture outside law to use an EBSCOhost database, the # can be used to look for word variations. For example, type "colo#r" to find all citations containing "color" or "colour." This is basically the opposite of Westlaw's search syntax.

How are you supposed to remember such arcana? You don't have to—just remember that the different search systems all have help screens that you can refer to when you have a special need.

Of course, the real boom in # use is not in obscure database search options. As GQ said when it named # the "symbol of the year" in 2010:

Just a couple of years ago, our little friend # was nearly irrelevant, relegated to the lonely domains of foam fingers (we're #1!) and robocalls (press # for more options). But these days, along with its boyfriend @, # is leading the charge in the Twitter Revolution (#SorryISaidTwitterRevolution). Hashtags have changed the way we think, communicate, process information.

Because I used a # in this post's headline, the Twitter version of this post will be linked to all the other nerdy tweets about National Punctuation Day. That's a power little symbol!