From a German point of view, Hajo is also a short form - or rather an established calling name - for combined names with Ha* and Jo*/Jö* - "Hans-Jakob, Hans-Johann, Hans-Joachim, Hans-Jörg/Hansjörg, " and alike. Might also be used with combinations starting with other Ha*-names (e.g. Hartmut or Harald), as well as with names starting with He* (e.g. Helmut or Heinz).
Might also be used with combinations starting with other Ha*-names (e.g. Hartmut or Harald), as well as with names starting with He* (e.g. Helmut or Heinz).