2.4 Miscellaneous

There are a few other changes in the HTML syntax worthy of mentioning:

• The ⟨ and ⟩ named character references now expand to U+27E8 and U+27E9 instead of U+2329 and U+232A, respectively.

• Many new named character references have been added, including all from MathML.

• Void elements (known as "EMPTY" in HTML4) are allowed to have a trailing slash.

• The ampersand (&) may be left unescaped in some more cases compared to HTML4.

• Attributes have to be separated by at least one whitespace character.

• Attributes with an empty value may be written as just the attribute name omitting the equals sign and the value, even if it's not a boolean attribute. (HTML4 actually allowed using only the attribute value and omitting the attribute name, for enumerated attributes, but this was not supported in browsers.)

• Attributes omitting quotes for the value are allowed to use a larger set of characters compared to HTML4.

• The optgroup end tag is now optional.

• The colgroup start tag is now optional and is inferred by the HTML parser.

• viod elements
• EMPTY
• single closing tag
• 위는 전부 같은 것을 말하고, <meta {...} /> 같은 형식의 닫는 태그가 없는 것을 의미한다.