Sec. 17. Construction where instrument is ambiguous. - Where the language  of  the  instrument  is  ambiguous  or  there  are  omissions therein, the following rules of construction apply:
      (a)  Where  the  sum  payable  is  expressed  in  words  and  also  in figures  and  there  is  a  discrepancy  between  the  two,  the  sum denoted  by  the  words  is  the  sum  payable;  but  if  the  words  are ambiguous or uncertain, reference may be had to the figures to fix
the amount;
      (b) Where the instrument provides for the payment of interest, without  specifying  the  date  from  which  interest  is  to  run,  the interest runs from the date of the instrument, and if the instrument is undated, from the issue thereof;
      (c) Where the instrument is not dated, it will be considered to be dated as of the time it was issued;
      (d)  Where  there  is  a  conflict  between  the  written  and  printed provisions of the instrument, the written provisions prevail;
      (e)  Where  the instrument is so  ambiguous that there is  doubt whether it is a bill or note, the holder may treat it as either at his election;
      (f) Where a signature is so placed upon the instrument that it is not clear in what capacity the person making the same intended to sign, he is to be deemed an indorser;
      (g)  Where  an  instrument  containing  the  word  "I  promise  to pay"  is  signed  by  two  or  more  persons,  they  are  deemed  to  be jointly and severally liable thereon. 



      Rules stated in this section shall not be availed of if the terms of the instrument in question is clear and admit of no doubt
      Applicable  only  when  the  instrument  in  question  is  ambiguous, doubtful or obscure, or when there are omissions therein that the