.ietf.org/html/rfc4647">RFC 4647 Matching of Language Tags. A language range is an identifier which is used to select language tag(s) meeting specific requirements by using the mechanisms described in
Locale Matching. A list which represents a user's preferences and consists of language ranges is called a
Language Priority List.
There are two types of language ranges: basic and extended. In RFC 4647, the syntax of language ranges is expressed in ABNF as follows:
basic-language-range = (1*8ALPHA *("-" 1*8alphanum)) / "*" extended-language-range = (1*8ALPHA / "*") *("-" (1*8alphanum / "*")) alphanum = ALPHA / DIGIT
For example, {@code "en"} (English), {@code "ja-JP"} (Japanese, Japan),{@code "*"} (special language range which matches any language tag) arebasic language ranges, whereas {@code "*-CH"} (any languages,Switzerland), {@code "es-*"} (Spanish, any regions), and{@code "zh-Hant-*"} (Traditional Chinese, any regions) are extendedlanguage ranges.
@see #filter
@see #filterTags
@see #lookup
@see #lookupTag
@since 1.8