wp-includes/functions.php:7641Retrieves a canonical form of the provided charset appropriate for passing to PHP functions such as htmlspecialchars() and charset HTML attributes.
$charsetstringstringfunction _canonical_charset( $charset ) { if ( is_utf8_charset( $charset ) ) { return 'UTF-8'; } /* * Normalize the ISO-8859-1 family of languages. * * This is not required for htmlspecialchars(), as it properly recognizes all of * the input character sets that here are transformed into "ISO-8859-1". * * @todo Should this entire check be removed since it's not required for the stated purpose? * @todo Should WordPress transform other potential charset equivalents, such as "latin1"? */ if ( ( 0 === strcasecmp( 'iso-8859-1', $charset ) ) || ( 0 === strcasecmp( 'iso8859-1', $charset ) ) ) { return 'ISO-8859-1'; } return $charset;}Introduced in 3.6.0. Unchanged from 6.7.7 through 7.1.0.
Signature, return type and hooks compared across 5 parsed releases.
src/wp-includes/functions.php, and regenerated for each WordPress release so it tracks the code rather than a snapshot of it.