Reference card

A reference card or quick reference card is a concise bundling of common syntactic rules and idioms of a particular formal language. It serves as an ad hoc memory aid for an experienced user.

In spite of what the name reference card suggest, the term only tends to be used in the narrow context of programming languages or markup languages. However, this concept is now being adopted to portray concise information in many other fields.

Appearance

Due to its logical structure and conciseness, finding information in a reference card is trivial for humans and requires no computer interaction. It is therefore convenient for a user to print out a reference card. This in contrast to user guides, which tend to be large & verbose and to have a very low information density (in comparison to reference cards).

Examples

• Wikimedia wiki syntax ref card meta:Help:Reference card
• A LaTeX reference sheet (PDF)
• An AMS LaTeX [1] (PDF)
• An R reference card [2] (PDF)
• An R reference card for data mining [3] (PDF)

See also

• Cheat sheet
• User guide

External links

• The "refcards.com" collection of reference cards
• Collection of reference cards
• Directory of cheat sheets and quick reference cards