Allow digit, '*', and '#' characters and meaning characters that include 'x', '.', '|' and range format characters that include '~', ',' and parenthesis '(', ')' and brackets '[', ']' and at most one parenthesis pair and 'T' for terminate are allowed and two quotation marks '()' means a null pattern for hot dial. examples: '002(x.)', '0(x.)', and '(x.)' 'x' represents any digit, '*', and '#' characters '.' represents zero or more repetitions of character or range that precedes it, can't use the dot character '.' in brackets '|' used to separate multiple dialplan patterns '[' and ']' must pair and nest brackets is illegal '~' and ',' are allowed showing in brackets only '~' connected characters must be digit 'T' stand for '#' to terminate and dial out at once Note: If only pattern is set, the indexed <pattern> <rule> pair will be cleared '\t' and '\r' is for partial pattern