In desktop publishing, typographer's marks refers to certain special characters that don't appear on a standard keyboard. These special characters are called typographer's marks because until word processing and page layout software made them more accessible to everyday users, they were used primarily by professional typographers (typesetters).
They are usually accessed by typing a series of keystrokes. These typographer's marks or typographical punctuation marks include curly quotation marks, a proper curly apostrophe, en dash, em dash, and ellipsis.
Typewritten material, emails, and other communications often use what is called the typewriter equivalent of proper typographer's marks. These include using a double hyphen in place of an em dash, using the double quote marks key in place of both the proper opening and closing double quotation marks, and typing a bunch of periods in place of the ellipsis. When found in typeset material, failure to use typographer's marks is often seen as a sign of laziness or amateur text composition.