the form feed as asterisks; 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. See also Carriage control tape Newline References Control characters