see: man 7 man
test on-screen: groff -Tlatin1 -man pdftk.1 | less
or: man ./pdftk.1
create text version: groff -Tascii -man pdftk.1 | col -b > pdftk.1.txt
create html version: groff -Thtml -man pdftk.1 > pdftk.1.html
for Windows compatibility:
todos pdftk.1.txt