On postcards, photographers are usually listed in the lower left corner. These are often abbreviations. For example, Zdeněk Menec is on some
postcards also listed as Z. Menec or Zd. Menec.
This leads, for example, to the fact that for some more common names the author cannot be clearly identified - if it is stated on the postcard
name M. Legutky, so it is impossible to say whether it is Michal Legutky or Milan Legutky, who are mentioned in this way on some postcards.