The default value for the format attribute is 1. Format tokens are a superset of the allowed values for the type attribute for the OL element in HTML 4.0 and are interpreted as follows: Any token where the last character has a decimal digit value of 1 generates a decimal representation of the number where each number is at least as long as the format token. Thus, a format token 1 generates the sequence 1 2 ... 10 11 12 ..., and a format token 01 generates the sequence 01 02 ... 09 10 11 12 ... 99 100 101. A format token A generates the sequence A B C ... Z AA AB AC.... . A format token a generates the sequence a b c ... z aa ab ac.... A format token i generates the sequence i ii iii iv v vi vii viii ix x .... A format token I generates the sequence I II III IV V VI VII VIII IX X .... Any other format token indicates a numbering sequence that starts with that token. If an implementation does not support a numbering sequence that starts with that token, it must use a format token of 1.