Question mark

The Question Mark (?), also known as an Interrogation mark, is a punctuation mark which is used to denote than a sentence is interrogative (asks a question). It may also be used as a placeholder when an answer is unknown or to be discovered; e.g. ''The combination of ??? and potassium is...''

The question mark may be accessed on the standard QWERTY keyboard by holding shift and pressing forward slash (/); its alt-code is alt+63.