Section 5--106. Issuance, amendment, cancellation, and duration

(a) A  letter of credit is issued and becomes enforceable according to
  its terms  against  the  issuer  when  the  issuer  sends  or  otherwise
  transmits  it to the person requested to advise or to the beneficiary. A
  letter of credit is revocable only if it so provides.
    (b) After a letter of credit is issued, rights and  obligations  of  a
  beneficiary,  applicant,  confirmer,  and  issuer are not affected by an
  amendment or cancellation to which that person has not consented  except
  to the extent the letter of credit provides that it is revocable or that
  the  issuer  may  amend  or  cancel  the  letter  of credit without that
  consent.
    (c) If there is no stated expiration  date  or  other  provision  that
  determines  its  duration, a letter of credit expires one year after its
  stated date of issuance or, if none is stated, after the date  on  which
  it is issued.
    (d) A  letter  of credit that states that it is perpetual expires five
  years after its stated date of issuance, or if none is stated, after the
  date on which it is issued.