Sarcasm convention is /s. Italics could be a quote:
Poe's law is an
adage of
Internet culture stating that, without a clear indicator of the author's intent, it is impossible to create a
parody of
extreme views so obviously exaggerated that it cannot be mistaken by some readers for a sincere expression of the parodied views.
Without the voice inflection and body language of personal communication these are easily misinterpreted. A /s, has become widely accepted on the net as an indication that "I'm only kidding". If you submit a satiric item without this symbol, no matter how obvious the satire is to you, do not be surprised if people take it seriously.