In information handling, the U.S. Federal Standard 1037C defines a hard copy as a permanent reproduction, or copy, in the form of a physical object, of any media suitable for direct use by a person, of displayed or transmitted data. Examples of hard copy include teleprinter pages, continuous printed tapes, computer printouts, and radio photo prints. On the other hand, physical objects such as magnetic tapes diskettes, or non-printed punched paper tapes are not defined as hard copy by 1037C. A file which can be viewed on a screen without printing it out is sometimes called a soft copy. The U.S. Federal Standard 1037C defines "soft copy" as "a nonpermanent display image, for example, a cathode ray tube display." The term "hard copy" predates the age of the digital computer. In the process of producing printed books and newspapers, hard copy refers to a manuscript or typewritten document that has been edited and proofread, and is ready for typesetting, or being read on-air in a radio or television broadcast. This traditional meaning has been all but forgotten in the wake of the information revolution.
One often-overlooked application for dot-matrix printers is in the field of IT security. Copies of various system and server activity logs are typically stored on the local filesystem, where a remote attacker – having achieved their primary goals – can then alter or delete the contents of the logs, in an attempt to "cover their tracks" or otherwise thwart the efforts of system administrators and security experts. However, if the log entries are simultaneously output to a printer, line-by-line, a local hard-copy record of system activity is created – and this cannot be remotely altered or otherwise manipulated. Dot-matrix printers are ideal for this task, as they can sequentially print each log entry, one entry at a time, as they are added to the log. The usual dot-matrix printer support for continuous stationery also prevents incriminating pages from being surreptitiously removed or altered without evidence of tampering.
"Dead-tree" dysphemism
The hacker's Jargon File defines a dead-tree version to be a paper version of an on-line document, where "dead trees" refer to paper. It is a dysphemism for hard copy. A saying from the Jargon File is that "You can't grep dead trees", from the Unix commandgrep meaning to search the contents of text files. This means that an advantage of keeping documents in digital form rather than on paper is that they can be more easily searched for specific contents. A yet another usage of this imagery, cited in Jargon File is "tree-killer", which may refer either to a printer or a person who wastes paper, for example marketing people who generate much "content-free" documentation. Dead-tree edition refers to a printed paper version of a written work, as opposed to digital alternatives such as a web page.
