A page break is a marker in an electronic document 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.
Form feed is seldom used when programming with modern printers in modern operating environments like Windows, Unix, Linux or macOS. Instead, form feeds are generated by having the printing program call a form feed API function. For example, when printing using the .NET Framework, the property is used to indicate a form feed is desired.
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 and vi, have built-in commands to page up/down on the form feed character. This convention is predominantly used in Lisp code, and is also seen in C and Python source code.
In Usenet, 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 spoilers from being inadvertently revealed. Spoilers on newsreaders.com The precise behavior depends on the client displaying the article: for example, Gnus displays "Next page..." in boldface, and switches to a second screen to display text after the form feed; slrn displays all non-space characters following the form feed as ; 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, IETF USEFOR USEAGE Draft as a feature that user agents should (but are not required to) support.