At sign in Morse code

The ITU's Radiocommunication Bureau added @ to the official Morse character set on May 24, 2004, the 160th anniversary of the first public telegraph message, What hath God wrought. ITU-R M.1677-1 lists it last among its signs, under the name commercial at.

The ARRL reported it as the first official addition to the Morse character set since World War I.

Split the six elements after the second one and you hear A, .-, flowing straight into C, -.-., with no letter gap. The pairing was reportedly chosen for "A[t] C[ommercial]", or for the look of the sign itself: a small a inside a curl like a C.

The rhythm is short, long, long, short, long, short, about 1.13 seconds at 18 WPM.

• The apostrophe, .----., has a dash where @ has its fourth element, a dot.
• The quotation mark, .-..-., has a dot where @ has its third element, a dash.
• The letter P, .--., is the first four elements of @ on their own.

All three marks have six elements and begin and end on a dot, so the middle is where to listen.

Spell the address one character at a time with normal letter gaps, using the at sign and the period where they fall. ME@HOME, the word in this page's practice box, is -- . .--.-. .... --- -- ., seven characters and 69 units, about 4.6 seconds at 18 WPM.

Most real addresses also contain a dot. Each one is sent as the period signal, and the receiver writes it as a dot because the context shows an address, not the end of a sentence.