A reference card or reference sheet (or quick reference card) or crib sheet is a concise bundling of condensed notes about a specific topic, such as mathematical formulas to calculate area/volume, or common

syntactic In linguistics, syntax () is the study of how words and morphemes combine to form larger units such as phrases and sentences. Central concerns of syntax include word order, grammatical relations, hierarchical sentence structure (constituency), ...

rules and idioms of a particular

computer platform A computing platform or digital platform is an environment in which a piece of software is executed. It may be the hardware or the operating system (OS), even a web browser and associated application programming interfaces, or other underlying s ...

application program Application may refer to: Mathematics and computing * Application software, computer software designed to help the user to perform specific tasks ** Application layer, an abstraction layer that specifies protocols and interface methods used in a ...

, or

formal language In logic, mathematics, computer science, and linguistics, a formal language consists of words whose letters are taken from an alphabet and are well-formed according to a specific set of rules. The alphabet of a formal language consists of symb ...

. It serves as an ad hoc

memory Memory is the faculty of the mind by which data or information is encoded, stored, and retrieved when needed. It is the retention of information over time for the purpose of influencing future action. If past events could not be remembered, ...

aid for an experienced user. In spite of what the name ''reference card'' may suggest, such as a 3x5

index card An index card (or record card in British English and system cards in Australian English) consists of card stock (heavy paper) cut to a standard size, used for recording and storing small amounts of discrete data. A collection of such cards e ...

(), the term also applies to sheets of paper or online pages, as in the context of

programming language A programming language is a system of notation for writing computer programs. Most programming languages are text-based formal languages, but they may also be graphical. They are a kind of computer language. The description of a programming ...

s or

markup language Markup language refers to a text-encoding system consisting of a set of symbols inserted in a text document to control its structure, formatting, or the relationship between its parts. Markup is often used to control the display of the document ...

s. However, this concept is now being adopted to portray concise information in many other fields.

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As in the examples below, reference cards are typically one to a few pages in length. Pages are organized into one or more columns. Across the columns, the reference is split into sections and organized by topic. Each section contains a list of entries, with each entry containing a term and its description and usage information. Terms might include keywords, syntactic constructs, functions, methods, or macros in a computer language. In a reference card for a program with a graphical user interface, terms may include menu entries, icons or key combinations representing program actions. 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. While reference cards can be printed on

card stock Card stock, also called cover stock and pasteboard, is paper that is thicker and more durable than normal writing and printing paper, but thinner and more flexible than other forms of paperboard. Card stock is often used for business cards, ...

, it is common to print them on ordinary printer paper. With the advent of portable electronic devices that can display documents, digital reference cards stored in

PDF Portable Document Format (PDF), standardized as ISO 32000, is a file format developed by Adobe in 1992 to present documents, including text formatting and images, in a manner independent of application software, hardware, and operating systems. ...

HTML The HyperText Markup Language or HTML is the standard markup language for documents designed to be displayed in a web browser. It can be assisted by technologies such as Cascading Style Sheets (CSS) and scripting languages such as JavaScri ...

formats have become more common. This is in contrast to

user guide A user guide, also commonly known as a user manual, is intended to assist users in using a particular product, service or application. It's usually written by a technician, product developer, or a company's customer service staff. Most user guid ...

s, which tend to be rather long and verbose and which have (in comparison to reference cards) a lower information density

Examples

* Wikimedia wiki syntax ref card meta:Help:Reference card * A

LaTeX Latex is an emulsion (stable dispersion) of polymer microparticles in water. Latexes are found in nature, but synthetic latexes are common as well. In nature, latex is found as a milky fluid found in 10% of all flowering plants (angiosperms ...

reference sheet
PDF
* An AMS

reference card
PDF
* An R reference card
PDF
* An R reference card for data mining
www.rdatamining.com
* A

CC (common criteria) CC, cc, or C-C may refer to: Arts, entertainment, and media Fictional characters * C.C. (''Code Geass''), a character in the ''Code Geass'' anime series, pronounced "C-two" * C.C. Babcock, a character in the American sitcom ''The Nanny'' * Come ...

quick reference card for

security product evaluation Security is protection from, or resilience against, potential harm (or other unwanted coercive change) caused by others, by restraining the freedom of others to act. Beneficiaries (technically referents) of security may be of persons and social ...

References

Technical communication {{compu-stub pl:Ściąga#Inne rodzaje ściąg

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Examples

See also

References