regex - Used to escape regular expression special characters
json - Used to escape JSON special characters
javascript - Used to escape Javascript special characters
html - Used to escape HTML special characters
xml - Used to escape XML special characters
java - Used to escape Java special characters
sql - Used to escape SQL special characters
url - Used to escape URL special characters
nl2br - Used to convert new line character to <br> HTML tag
separator(SEPARATOR_CHARS) - Used to change the default separator ";" to the SEPARATOR_CHARS. eg. ?separator(, ) resulted "abc, def" instead of "abc;def".
img2base64 - hashvariable escape method to convert image tag src in a Rich Text Editor tobase64data string which can be displayed in email (however Gmail does not support Base64).