law: Indian Stamp Act, 1899 
  31. Adjudication as to proper stamp 
  (1) When any instrument, whether executed or not and whether
  
  previously stamped or not, is brought to the Collector, and the person bringing
  
  it applies to have the opinion of that officer as to the duty (if any) with
  
  which it is chargeable, and pays a fee of such amount (not exceeding five
  
  rupees and not less than 40[fifty naye paise]) as the Collector may
  
  in each case direct, the Collector shall determine the duty (if any) with
  
  which, in his judgment the instrument is chargeable.
  (2) For this purpose the Collector may require to be furnished
  
  with an abstract of the instrument, and also with such affidavit or other
  
  evidence as he may deem necessary to prove that all the facts and circumstances
  
  affecting the chargeability of the instrument with duty, or the amount of the
  
  duty with which it is chargeable, are fully and truly set forth therein, and
  
  may refuse to proceed upon any such application until such abstract and
  
  evidence have been furnished accordingly:
  PROVIDED  that- 
  (a) no evidence furnished in pursuance of this section shall be
  
  used against any person in any civil proceeding, except in an enquiry as to the
  
  duty with which the instrument to which it relates is chargeable; and
  (b) every person by whom any such evidence is furnished, shall,
  
  on payment of the full duty with which the instrument to which it relates, is
  
  chargeable, be relieved from any penalty which he may have incurred under this
  
  Act by reason of the omission to state truly in such instrument any of the
  
  facts or circumstances aforesaid.