simple to begin with:
\c $ lns subdir2 subdir3
-\c bbbbbbbbbbbbbbbbbbb
+\e bbbbbbbbbbbbbbbbbbb
This creates a symlink called \cw{subdir3} with text \cq{subdir2}.
\cw{subdir} instead of \cw{subdir2}. If I do this:
\c $ lns -f subdir subdir3
-\c bbbbbbbbbbbbbbbbbbbbb
+\e bbbbbbbbbbbbbbbbbbbbb
then \cw{lns} will immediately notice that the second argument
\cw{subdir3} is (a symlink to) a directory, and will therefore
\cw{-F} option:
\c $ lns -F subdir subdir3
-\c bbbbbbbbbbbbbbbbbbbbb
+\e bbbbbbbbbbbbbbbbbbbbb
\cw{-F} tells \cw{lns} that you really want the new symlink to be
\e{called} \cw{subdir3}, not to be \e{in the directory}