just have a look at my signature :-) There, -l stands for adding a newline at the end. I especially use -l for oneliners. If I use it in real programs, I have to to write some comments about why using it, so I hardly ever use it there.
Best regards,
perl -le "s==*F=e=>y~\*martinF~stronat~=>s~[^\w]~~g=>chop,print"