The interrobang is a combination of the exclamation point (!), and a question mark (?). Though it seems fake, it is an actual punctuation mark. A sentence ending with an interrobang either (1) asks a question in an excited manner, (2) expresses excitement or disbelief in the form of a question, or (3) asks a rhetorical question. A reverse and upside down interrobang (combining ¿ and ¡), suitable for starting phrases in Spanish, Asturian, and Galician, is called by some a gnaborretni.
Martin K. Speckter is the inventor of the interrobang (1962). The French equivalent is "point exclarrogatif."
The irony mark is a backward question mark. The irony mark (؟) (French: point d’ironie) is a punctuation mark that purports to indicate that a sentence should be understood at a second level. An irony mark may sometimes be referred to as an irony point, snark, or zing. Its usage is extremely rare. This mark was proposed by the French poet Alcanter de Brahm at the end of the 19th century. At the end of a sentence, put a backward exclamation point (؟) to indicate irony if it is to be known to the whole audience that the text is ironic.Irony is often intended to be misunderstood by a certain portion of its audience, either to enforce close attention or to create a boundary between those "in the know" and those who miss the point. Explicit use of an irony mark in such a circumstance would defeat the purpose of using "le point d'ironie."
May your mouth never be conquered by a band of marauding Vikings,