Function: Sanitizes content from bad protocols and other characters.

Function: Builds an attribute list from string containing attributes.

Function: Performs different checks for attribute values.

Function: Sanitizes a string and removed disallowed URL protocols.

Function: Removes any invalid control characters in a text string.

Function: Strips slashes from in front of quotes.

Function: Converts the keys of an array to lowercase.

Function: Handles parsing errors in `wp_kses_hair()`.

Function: Removes all attributes, if none are allowed for this element.

Function: Filters text content and strips out disallowed HTML.