The pirate-english tag is for questions on the stereotypical sociolect of English that was supposedly spoken by seafaring pirates in the Golden Age of Piracy. It is represented in many works of fiction, such as The Pirates of Penzance and many incarnations of Treasure Island, and in the modern joke holiday of International Talk Like a Pirate Day.
Pirate English incorporates much nautical jargon, as well as pirate-specific terms like "(y)arrrr(gh)", "yo-ho-ho", and "Shiver me timbers!". It is influenced by the dialects of South-West England.
The extent that pirates actually talked this way is discussed in What is the factual basis for "pirate speech"? (Did pirates really say things like "shiver me timbers"?).