Wikipedia:ASCII

Purpose

 * This is a reference to the 128 ASCII codes for programmer convienience.
 * It is not expected that it be included in anything, but act as a look-up at need for templates where hard coding of a character is needed to work around undesirable preprossing effects during the the parsing and expansion of a template line.
 * Such codes can be entered using the format prefix=' &# ', Suffix=';' both sandwiched about the decimal code value like the examples immediately below.

ASCII printable characters
Code 32, the "space" character, denotes the space between words, as produced by the large space-bar of a keyboard. Codes 33 to 126, known as the printable characters, represent letters, digits, punctuation marks, and a few miscellaneous symbols.

Seven-bit ASCII provided seven "national" characters and, if the combined hardware and software permit, can use overstrikes to simulate some additional international characters: in such a scenario a backspace can precede a grave accent (which the American and British standards, but only those standards, also call "opening single quotation mark"), a tilde, or a breath mark (inverted vel).