Question mark
In the early 13th century, when the growth of communities of scholars (universities) in Paris and other major cities led to an expansion and streamlining of the book-production trade, punctuation was rationalized by assigning Alcuin's stroke-over-dot specifically to interrogatives; by this time the stroke was more sharply curved and can easily be recognized as the modern question mark.
Sarcasm
Though in the English language there is no standard accepted method to denote irony or sarcasm in written conversation, several forms of punctuation have been proposed. Among the oldest and frequently attested are the percontation point—furthered by Henry Denham in the 1580s—and the irony mark—furthered by Alcanter de Brahm in the 19th century. Both of these marks were represented visually by a ⸮ backwards question mark (unicode U+2E2E). Each of these punctuation marks are primarily used to indicate that a sentence should be understood as ironic, but not necessarily designate sarcasm that is not ironic. By contrast, more recent proposals, such as the snark mark, or the use of a following tilde are specifically intended to denote sarcasm rather than irony. A bracketed exclamation point or question mark as well as scare quotes are also sometimes used to express irony or ironic sarcasm.