WHAT THE ####?

You call it ‘hash’, ‘gate’ or ‘square’. The Americans call it the ‘pound’ sign but the technical name in information technology circles is octothorpe. The following article contributed to Usenet on the Internet by Ralph Carlsen  explains where the name ‘octothorpe’ really came from.  Over to Ralph...

I am sending this to you because, as you will see, there are very few people who could know this story.  The reason I am writing at this time is because I volunteered for the AT&T Lay-Off package after 34 years of service at Bell Labs so I may not be around much longer.

                      Ralph Carlsen


First, where did the symbols * and # come from?  In about 1961 when DTMF dials were still in development, two Bell Labs guys in data communications engineering (Link Rice and Jack Soderberg) toured the USA talking to people who were thinking about telephone access to computers.  They asked about possible applications, and what symbols should be used on two keys that would be used exclusively for data applications.  The primary result was that the symbols should be something available on all standard typewriter keyboards.  The * and # were selected as a result of this study, and people did not expect to use those keys for voice services.  The Bell System in those days did not look internationally to see if this was a good choice for foreign countries.

Then in the early 1960s Bell Labs developed the 101 ESS  (Electronic Switching System, a pioneer electronic exchange) which was the first stored program controlled switching system (it was a PBX).  One of the first installations was at the Mayo Clinic.  This PBX had lots of modern features (Call Forwarding, Speed Calling, Directed Call Pickup, etc.), some of which were activated by using the # sign.

A Bell Labs supervisor DON MACPHERSON went to the Mayo Clinic just before cut-over to train the doctors and staff on how to use the new features on this state of the art switching system.  During one of his lectures he felt the need to come up with a word to describe the # symbol.  Don also liked to add humour to his work.  His thought process which took place while at the Mayo Clinic doing lectures was as follows:

·   There are eight points on the symbol so ‘OCTO’ should be part of the name.

·   We need a few more letters or another syllable to make a noun, so what should that be?  (Don MacPherson at this point in his life was active in a group that was trying to get JIM THORPE's Olympic medals returned from Sweden) The phrase THORPE would be unique, and people would not suspect he was making the word up if he called it an ‘OCTOTHORPE’.

So Don Macpherson began using the term Octothorpe to describe the # symbol in his lectures.  When he returned to Bell Labs in Holmdel NJ, he told us what he had done, and began using the term Octothorpe in memos and letters.  The term was picked up by other Bell Labs people and used mostly for the fun of it.  Some of the documents which used the term Octothorpe found their way to Bell Operating Companies and other public places.  Over the years, Don and I have enjoyed seeing the term Octothorpe appear in documents from many different sources.

Don MacPherson retired about eight years ago, and I will be retiring in about six weeks. These are, of course, my remembrances and are not any official statement of AT&T or the subsequent companies.

And another item spotted on the Internet...

There is a CCITT (now ITU-T) specification for the * and # keys on the phone. BT generally follow such specifications. You would be amazed how difficult it is companies to follow them when you are just an engineer and are having to deal with marketing types. (How many phones have un-crossed zeros on the display ?)

Indeed, it is the same specification that ensures all phones have 1 2 3 at the top and *0# at the bottom (don't nit-pick about non 3 x 4 keypads, they are covered also).

The specification is ITU-T E.161 3.2.2 :-

The * is to be known as "star" or equivalent in other languages. It is a six pointed star, with 60 degree angles, and orientated such as to have a horizontal line.

The # is to be known as a "square" or the most commonly used equivalent term in other languages. This symbol shall consist of four lines of equal length forming two pairs of parallel lines. One pair is horizontal while the other is vertical or inclined to the right at an angle of 80 degrees. It will be seen that the two pairs of lines overlap. The ratio a/b, where a is the overlap and b is the length of the lines, shall be between 0.08 and 0.18.

The preferred values are In Europe, 90 degrees, a/b=0.08 In North America, 80 degrees, a/b close to the upper limit of 0.18. So BT is quite correct, and it has nothing to do with ignoring the Americans.

Adrian Kennard


John Moynihan in Australia adds:

I downloaded ITU-T E.161 from Geneva (issued 05/95) and my copy of para 3.2.2  now says simply:-

"The symbol will be known as the star (in italics) or the equivalent in other languages."

i.e. no mention of ' six pointed. '  However it says that (the button) "should have a shape easily identified as the general shape shown in Figure 2." Figure 2 is a 6 pointed symbol.  I'm not up on nitty gritty of hardware, but the current Telecom/Telstra button is 8 pointed.

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