Batch Module. Bug in -Z?

I run the example 2 of the batch docs but without -W and I after it finished I got a folder Name “countries” with 5 files inside (batch_init.sh, batch_job.sh, batch_postfligth.sh, batch_preflight.sh, countries.txt). Is it a bug in -Z?

BTW, I noticed that in the docs there is no description for -Zs but it is used in the second example.

cat << EOF > pre.sh
gmt begin
    gmt coast -E=EU+l > countries.txt
gmt end
EOF
cat << EOF > main.sh
gmt begin \${BATCH_NAME} pdf
    gmt coast -R\${BATCH_WORD0}+r2 -JQ10c -Glightgray -Slightblue -B -B+t"\${BATCH_WORD1}" -E\${BATCH_WORD0}+gred+p0.5p
    echo \${BATCH_WORD0} | gmt text -F+f16p+jTL+cTL -Gwhite -W1p
gmt end
EOF
cat << EOF > post.sh
gs -dQUIET -dNOPAUSE -sDEVICE=pdfwrite -sOUTPUTFILE=\${BATCH_PREFIX}.pdf -dBATCH \${BATCH_PREFIX}_*.pdf
rm -f \${BATCH_PREFIX}_*.pdf
EOF
gmt batch main.sh -Sbpre.sh -Sfpost.sh -Tcountries.txt+w"\t" -Ncountries -V -Zs