@fig{smiley1,
  main = {This is a smiley},
  add = {The additional description is meaningless},
  caption = {Smiley},
  file = {smiley}
}

@fig{smiley2,
  main = {Here is the smiley again},
  file = {smiley}
}

@fig{smiley3,
  main = {Yet another smiley},
  file = {smiley},
  source = {(top secret)}
}