Decimal Notation in HTML

The hyphen you can insert with the key next to the zero on your keyboard is an ambiguous character suffering from an identity crisis.
It can't decide if it's a hyphen -, a minus −, an em dash — or an en dash –.

The Unicode specification describes the key as a hyphen-minus and defines very specific replacements for its use.

Use it to insert a hyphen, but never for a minus or a dash, since it does not have the correct width for either, or the vertical position for the latter.

Neither an em dash nor an en dash should be confused with the hyphen, which has the following functions:

1. To join compound words together.
2. To connect compound words
3. To connect the syllables of words broken at the ends of lines
4. To connect prefixes and suffixes to words

The modern trend is away from hyphenation, and to eliminate the hyphen after a prefix.

Hyphens are always required with the following prefixes:

• half
• quarter
• quasi
• self
• ex
• all

Permanent compounds tend to become solid, and temporary compounds tend to be hyphenated only when necessary to avoid ambiguity.

Hyphens in Decimal Notation

Character	Notes	Code	Render
hyphen	punctuation	-	-
minus	mathematical	−	−
hyphen character	punctuation	‐	‐
non-breaking	does what its name implies	‑	‑
soft hyphen	indicates where a word may be broken at the end of a line	­	a­b
hyphen point	punctuation	‧	‧
hyphen bullet	punctuation	⁃	⁃
z1 double oblique	punctuation	⸗	⸗
z1 with diaeresis	punctuation	⸚	⸚