let quot = Utf8_char.of_char '"'
let semicolon = Utf8_char.of_char ';'
let amp = Utf8_char.of_char '&'
let hash = Utf8_char.of_char '#'
let lt = Utf8_char.of_char '<'
let gt = Utf8_char.of_char '>'
let bkslash = Utf8_char.of_char '\\'
let apos = Utf8_char.of_char '\''
let quot = Utf8_char.of_char '"'
let colon = Utf8_char.of_char ':'
let eq = Utf8_char.of_char '='
let uscore = Utf8_char.of_char '_'
let slash = Utf8_char.of_char '/'
let ques = Utf8_char.of_char '?'
let excl = Utf8_char.of_char '!'
let openbr = Utf8_char.of_char '['
let closebr = Utf8_char.of_char ']'
let dash = Utf8_char.of_char '-'

let twodashes = "--"
let quesgt = "?>"
let openbr_cdata_openbr = "[CDATA["