2012-04-01

Unicode use: The Wave Dash 〜

Perm URL with updates: http://xahlee.org/comp/unicode_symbols_use.html

This is the nth episode of Xah's rectification of typographical convention! (➲ The Writing Style on XahLee.orgThe Moronicities of Typography: Hyphen, Dash, Quotation Marks, Apostrophe)

Today, i decided to use the unicode WAVE DASH for date range.

Traditionally, it's done by a EN DASH . However, that has several ambiguity problems. It's impossible to tell it from a minus sign. This is especially important in scientific contexts. Quote from Wikipedia Dash:

The Guide for the Use of the International System of Units (SI) recommends that when a number range might be misconstrued as subtraction, the word “to” should be used instead of an en dash. For example, “a voltage of 50 V to 100 V” is preferable to using “a voltage of 50–100 V”. It is also considered inappropriate to use the en dash in place of the words to or and in phrases that follow the forms from … to … and between … and ….[9][10]

The sources [9] [10] are:

  • Judd, Karen (2001). Copyediting: A Practical Guide. Menlo Park, Calif: Crisp Publications. ISBN 1-56052-608-4.
  • Loberger, Gordon; Kate Shoup Welsh (2001). Webster's new world English grammar handbook. New York: Hungry Minds. ISBN 0-7645-6488-9.

A couple years ago ≈2009, i tested in browsers about displaying the wave dash. At the time, some browser doesn't show the char. But today, all major browsers do. At the time, i decided to use the FIGURE DASH for date range. Now, i replaced all of them on my site to the wave dash. About 480 occurrences.

For examples where date range happens a lot, see:

Use of ALMOST EQUAL TO ≈

Also, i often use the TILDE ~ in front of a year to indicate approximate date, e.g. {“I use Dvorak layout since ~1993”, “Place a ~5 cm thick book in front of the keyboard”}. I've been trying to find a proper symbol for that. The closest is the ALMOST EQUAL TO . But am not sure about that because that symbol should between 2 quantities, as a relation, in some strict sense. Anyhow, today i decided to adopt this symbol in front of a date/number to indicate approximate/in-exact date/quantity. Not completely satisfied, but it's still better than the promiscuous tilde. For files with several use of ≈, see: