Wiktionary
a. (context computing English) Consisting only of plain text. alt. 1 (context cryptography English) Not encrypted text; text that is readable. 2 (context computing English) Data which consists only of human-readable text, as opposed to machine-readable binary data or formatting markup. n. 1 (context cryptography English) Not encrypted text; text that is readable. 2 (context computing English) Data which consists only of human-readable text, as opposed to machine-readable binary data or formatting markup.
Wikipedia
In computing, plain text is the data (e.g. file contents) that represent only characters of readable material but not its graphical representation nor other objects (images, etc.). It may also include a limited number of characters that control simple arrangement of text, such as line breaks or tabulation characters. Plain text is different from formatted text, where style information is included, and from "binary files" in which some portions must be interpreted as binary objects (encoded integers, real numbers, images, etc.).
The encoding has traditionally been either ASCII, sometimes EBCDIC. Unicode-based encodings such as UTF-8 and UTF-16 are gradually replacing the older ASCII derivatives limited to 7 or 8 bit codes.
Usage examples of "plain text".
But he scanned those in plain text, and quickly he realized that something was different about this batch.
Badly scanned & previously released as a raw plain text output by unknown asshole (missing/doublescanned pages, no italics, lots of errors).
The usual faxes, calls and E-mail are plain text on ordinary machines, and I would love a shredder that actually worked.
You'll notice it records everything you've searched for in a search engine in plain text, in addition to the URL.
Someone in CVIC has broken the code already, giving me a plain text translation beneath the sequence of apparently random letters.
It was then compared to a plain text version which was created on February 10, 2002, and was labelled as version 4.
Because if you sent a plain text message, it would literally take hours.
This book had already been scanned by some unknown scanner and released in an UnCorrected (UC) plain text format.