/esc_url/) ` wp-includes/formatting.php ` |  Checks and cleans a URL.   
[ esc_js() ](https://developer.wordpress.org/reference/functions/esc_js/) ` wp-includes/formatting.php ` |  Escapes single quotes, ` " ` , ` ` , ` &amp; ` , and fixes line endings.   
[ esc_html() ](https://developer.wordpress.org/reference/functions/esc_html/) ` wp-includes/formatting.php ` |  Escaping for HTML blocks.   
[ esc_attr() ](https://developer.wordpress.org/reference/functions/esc_attr/) ` wp-includes/formatting.php ` |  Escaping for HTML attributes.   
[ wp_richedit_pre() ](https://developer.wordpress.org/reference/functions/wp_richedit_pre/) ` wp-includes/deprecated.php ` |  Formats text for the rich text editor.   
[ sanitize_email() ](https://developer.wordpress.org/reference/functions/sanitize_email/) ` wp-includes/formatting.php ` |  Strips out all characters that are not allowable in an email.   
[ human_time_diff() ](https://developer.wordpress.org/reference/functions/human_time_diff/) ` wp-includes/formatting.php ` |  Determines the difference between two timestamps.   
[ wp_trim_excerpt() ](https://developer.wordpress.org/reference/functions/wp_trim_excerpt/) ` wp-includes/formatting.php ` |  Generates an excerpt from the content, if needed.   
[ wp_trim_words() ](https://developer.wordpress.org/reference/functions/wp_trim_words/) ` wp-includes/formatting.php ` |  Trims text to a certain number of words.   
[ ent2ncr() ](https://developer.wordpress.org/reference/functions/ent2ncr/) ` wp-includes/formatting.php ` |  Converts named entities into numbered entities.   
[ translate_smiley() ](https://developer.wordpress.org/reference/functions/translate_smiley/) ` wp-includes/formatting.php ` |  Converts one smiley code to the icon graphic file equivalent.   
[ is_email() ](https://developer.wordpress.org/reference/functions/is_email/) ` wp-includes/formatting.php ` |  Verifies that an email is valid.   
[ sanitize_file_name() ](https://developer.wordpress.org/reference/functions/sanitize_file_name/) ` wp-includes/formatting.php ` |  Sanitizes a filename, replacing whitespace with dashes.   
[ sanitize_user() ](https://developer.wordpress.org/reference/functions/sanitize_user/) ` wp-includes/formatting.php ` |  Sanitizes a username, stripping out unsafe characters.   
[ sanitize_key() ](https://developer.wordpress.org/reference/functions/sanitize_key/) ` wp-includes/formatting.php ` |  Sanitizes a string key.   
[ sanitize_title() ](https://developer.wordpress.org/reference/functions/sanitize_title/) ` wp-includes/formatting.php ` |  Sanitizes a string into a slug, which can be used in URLs or HTML attributes.   
[ sanitize_html_class() ](https://developer.wordpress.org/reference/functions/sanitize_html_class/) ` wp-includes/formatting.php ` |  Sanitizes an HTML classname to ensure it only contains valid characters.   
[ format_to_edit() ](https://developer.wordpress.org/reference/functions/format_to_edit/) ` wp-includes/formatting.php ` |  Acts on text which is about to be edited.   
[ get_avatar() ](https://developer.wordpress.org/reference/functions/get_avatar/) ` wp-includes/pluggable.php ` |  Retrieves the avatar ` <img> ` tag for a user, email address, MD5 hash, comment, or post.   
[ wptexturize() ](https://developer.wordpress.org/reference/functions/wptexturize/) ` wp-includes/formatting.php ` |  Replaces common plain text characters with formatted entities.   
[ wp_password_change_notification() ](https://developer.wordpress.org/reference/functions/wp_password_change_notification/) ` wp-includes/pluggable.php ` |  Notifies the blog admin of a user changing password, normally via email.   
[ wp_new_user_notification() ](https://developer.wordpress.org/reference/functions/wp_new_user_notification/) ` wp-includes/pluggable.php ` |  Emails login credentials to a newly-registered user.   
[ wp_nonce_tick() ](https://developer.wordpress.org/reference/functions/wp_nonce_tick/) ` wp-includes/pluggable.php ` |  Returns the time-dependent