R.Muralikrishnan, MPI for Empirical Aesthetics. This work is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International Licence.
BEGIN{ Edges = (FS "$|^" FS); # This can also simply be Edges = "^"FS...apparently...and it seems to work.  But we still retain the original.

        # Adapted from REF: http://www.linuxquestions.org/questions/linux-general-1/awk-delete-defined-columns-4175426481/#post4777125
        # For removing a leading FS;
        # A trailing FS would apparently be: (FS "$")
        # The combination is what is used in the site above, as follows: (FS "$|^" FS).
        # See also the gsub command below, in which we use this variable to replace the pattern with          
}


{
gsub(/[0-9]/,""); # Replace all numbers with nothing.
gsub(/ \. /," "); # Replace the pattern " . " with a space. (That latter pattern would result in German texts, after removing the ordinal numbers...such as 63. Tag.

gsub(/--/," "); # Replace the pattern "--" with a space. (Eduard--so nennen wir ihn => Eduard so nennen wir ihn)
gsub(/- /," "); # Replace the pattern "- " with a space. (Dokumentar- und andere Filme => Dokumentar und andere Filme)
gsub(/-/," "); # Replace connecting hyphens with a space. (Doku-Serie => Doku Serie)

gsub(/’/,"") # Replace apostrophes with nothing. (father’s => fathers)
gsub(/,/,"") # Replace commas with nothing
gsub(/;/,"") # Replace semi-colons with nothing
gsub(/:/,"") # Replace colons with nothing

gsub(/\"/,"") # Replace double-quotes with nothing.
gsub(/«/,""); # Replace German opening-quote marks with nothing.
gsub(/»/,""); # Replace German closing-quote marks with nothing.


gsub(/\?/,"."); # Replace question-marks with a full-stop.
gsub(/\!/,"."); # Replace exclamation-marks with a full-stop.

gsub(Edges,""); # Replace leading/trailing FS with nothing. 

if (length($0)!=0){ print $0; }

}