Thanks for fast response
...and thanks for "grep" tip -just discovered I have it installed with Delphi (pascal). Now I must figure out it's usability :-)

About NULL... searching in this forum is somehow limited (I almost never get a hit). Anyway, if I understand correctly: If I put newline (CR+LF) somewhere into Copyright string, exiftool will automatically translate this into NULL character. I'll try this...

Bogdan