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A page break is a marker in an electronic
document A document is a written, drawn, presented, or memorialized representation of thought, often the manifestation of non-fictional, as well as fictional, content. The word originates from the Latin ''Documentum'', which denotes a "teaching" or ...
that tells the document interpreter that the content which follows is part of a new page. A page break causes a form feed to be sent to the printer during spooling of the document to the printer. Thus it is one of the elements that contributes to
pagination Pagination, also known as paging, is the process of dividing a document into discrete page (paper), pages, either electronic pages or printed pages. In reference to books produced without a computer, pagination can mean the consecutive page num ...
.


Form feed

Form feed is a page-breaking
ASCII ASCII ( ), abbreviated from American Standard Code for Information Interchange, is a character encoding standard for electronic communication. ASCII codes represent text in computers, telecommunications equipment, and other devices. Because of ...
control character In computing and telecommunication, a control Character (computing), character or non-printing character (NPC) is a code point (a number) in a character encoding, character set, that does not represent a written symbol. They are used as in-band ...
. It directs the
printer Printer may refer to: Technology * Printer (publishing), a person or a company * Printer (computing), a hardware device * Optical printer for motion picture films People * Nariman Printer (fl. c. 1940), Indian journalist and activist * James ...
to eject the current
page Page most commonly refers to: * Page (paper), one side of a leaf of paper, as in a book Page, PAGE, pages, or paging may also refer to: Roles * Page (assistance occupation), a professional occupation * Page (servant), traditionally a young m ...
and to continue printing at the top of another. Often, it will also cause a
carriage return A carriage return, sometimes known as a cartridge return and often shortened to CR, or return, is a control character or mechanism used to reset a device's position to the beginning of a line of text. It is closely associated with the line feed a ...
. The form feed character code is defined as 12 (0xC in
hexadecimal In mathematics and computing, the hexadecimal (also base-16 or simply hex) numeral system is a positional numeral system that represents numbers using a radix (base) of 16. Unlike the decimal system representing numbers using 10 symbols, hexa ...
), and may be represented as control+L or ^L. In a related use, control+L can be used to clear the screen in Unix shells such as
bash Bash or BASH may refer to: Arts and entertainment * ''Bash!'' (Rockapella album), 1992 * ''Bash!'' (Dave Bailey album), 1961 * '' Bash: Latter-Day Plays'', a dramatic triptych * ''BASH!'' (role-playing game), a 2005 superhero game * "Bash" ('' ...
. In the
C programming language ''The C Programming Language'' (sometimes termed ''K&R'', after its authors' initials) is a computer programming book written by Brian Kernighan and Dennis Ritchie, the latter of whom originally designed and implemented the language, as well as ...
(and other languages derived from C), the form feed character is represented as '\f'.
Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...
also provides the character as a printable symbol for a form feed (not as the form feed itself). The form feed character is considered whitespace by the
C character classification C character classification is an operation provided by a group of functions in the ANSI C Standard Library for the C programming language. These functions are used to test characters for membership in a particular class of characters, such as al ...
function isspace(). Form feed is seldom used when programming with modern printers in modern operating environments like
Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...
,
Unix Unix (; trademarked as UNIX) is a family of multitasking, multiuser computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, and ot ...
,
Linux Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, which ...
or
macOS macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and lapt ...
. Instead, form feeds are generated by having the printing program call a form feed
API An application programming interface (API) is a way for two or more computer programs to communicate with each other. It is a type of software interface, offering a service to other pieces of software. A document or standard that describes how ...
function. For example, when printing using the
.NET Framework The .NET Framework (pronounced as "''dot net"'') is a proprietary software framework developed by Microsoft that runs primarily on Microsoft Windows. It was the predominant implementation of the Common Language Infrastructure (CLI) until bein ...
, th
PrintPageEventArgs.HasMorePages property
is used to indicate a form feed is desired.


Semantic use

The form feed character is sometimes used in plain text files of source code as a delimiter for a page break, or as marker for sections of code. Some editors, in particular
emacs Emacs , originally named EMACS (an acronym for "Editor MACroS"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...
and vi, have built-in commands to page up/down on the form feed character. This convention is predominantly used in
Lisp A lisp is a speech impairment in which a person misarticulates sibilants (, , , , , , , ). These misarticulations often result in unclear speech. Types * A frontal lisp occurs when the tongue is placed anterior to the target. Interdental lisping ...
code, and is also seen in C and
Python Python may refer to: Snakes * Pythonidae, a family of nonvenomous snakes found in Africa, Asia, and Australia ** ''Python'' (genus), a genus of Pythonidae found in Africa and Asia * Python (mythology), a mythical serpent Computing * Python (pro ...
source code.
GNU GNU () is an extensive collection of free software (383 packages as of January 2022), which can be used as an operating system or can be used in parts with other operating systems. The use of the completed GNU tools led to the family of operat ...
Coding Standards require such form feeds in C. Editors like Vim and
Emacs Emacs , originally named EMACS (an acronym for "Editor MACroS"), is a family of text editors that are characterized by their extensibility. The manual for the most widely used variant, GNU Emacs, describes it as "the extensible, customizable, s ...
understand such sections and have shortcuts for moving among them. In
Usenet Usenet () is a worldwide distributed discussion system available on computers. It was developed from the general-purpose Unix-to-Unix Copy (UUCP) dial-up network architecture. Tom Truscott and Jim Ellis conceived the idea in 1979, and it was ...
, the form feed character is used by several newsreaders as a "spoiler character", causing them to automatically hide the following text until prompted, as a way to prevent
spoiler Spoiler is a security vulnerability on modern computer central processing units that use speculative execution. It exploits side-effects of speculative execution to improve the efficiency of Rowhammer and other related memory and cache attacks. Ac ...
s from being inadvertently revealed. The precise behavior depends on the client displaying the article: for example,
Gnus Gnus (), or Gnus Network User Services, is a message reader which is part of GNU Emacs. It supports reading and composing both e-mail and news and can also act as an RSS reader, web processor, and directory browser for both local and remote files ...
displays "Next page..." in boldface, and switches to a second screen to display text after the form feed;
slrn slrn is a console based news client for multiple operating systems, developed by John E. Davis and others. It was originally developed in 1994 for Unix-like operating systems and VMS, and now also supports Microsoft Windows. It supports scoring ...
displays all non-space characters following the form feed as
asterisk The asterisk ( ), from Late Latin , from Ancient Greek , ''asteriskos'', "little star", is a typographical symbol. It is so called because it resembles a conventional image of a heraldic star. Computer scientists and mathematicians often voc ...
s; Dialog turns the font and background color red between form feeds; and XRN simply inserts blank lines to fill up the remainder of the article display area so the user must scroll down to reveal the spoiler. This use of the form feed character is not supported by all newsreaders, and is not standardized, although it has appeared in a draft of a Usenet Best Practices document by the IETF's USEFOR working group, as a feature that user agents should (but are not required to) support.IETF USEFOR USEAGE Draft
/ref>


See also

*
Carriage control tape A carriage control tape was a loop of punched tape that was used to synchronize rapid vertical page movement in most IBM and many other line printers from unit record days through the 1980's. The tape loop was as long as the length of a single p ...
*
Newline Newline (frequently called line ending, end of line (EOL), next line (NEL) or line break) is a control character or sequence of control characters in character encoding specifications such as ASCII, EBCDIC, Unicode, etc. This character, or a ...


References

Control characters