TL;DR

TL;DR, short for "too long; didn't read", is an expression used in Internet culture to say that some text being replied to has been ignored or as a signifier for a summary of an online post or news article. It originates in Internet slang, where it is often used in quoted responses to indicate parts of the text skipped as too lengthy.

The abbreviation is based on the principle that, if the writer does not invest the time to convey their message concisely, the reader is justified not investing the time to read it. Alternately, it might mean that there is insufficient material of value or interest to justify the time required to read it.

The phrase dates back to at least 2003, and was added to the Oxford Dictionaries Online in 2013.^[1]

Eponyms

On reddit, tldr^[2] is the subreddit serving as the site's daily recap. Long posts on reddit are also frequently followed or preceded by a summary, consisting of a sentence or brief paragraph, that is prefixed by the phrase "TL;DR", and the abbreviation is sometimes used as a noun denoting such a summary, as in "Please include a TL;DR along with your post".

The phrase inspired the name of Terms of Service; Didn't Read, a website that aims to analyze and grade the terms of service and privacy policies of major service providers.^[3]

See also

• BLUF (communication): Bottom Line Up Front
• Lexicographic information cost

References

1. "Oxford Dictionaries Online quarterly update: new words added to oxforddictionaries.com today". OxfordWords blog. Oxford, UK: Oxford University Press. 28 August 2013. Retrieved 2014-12-04. TL;DR, abbrev.: ‘too long didn’t read’: used as a dismissive response to a lengthy online post, or to introduce a summary of a lengthy post.
2. "Too long; didn't read (TLDR or TL;DR)". reddit.
3. Caldwell, Patrick (August 14, 2012). "Too Long, Didn't Read My Rights". The American Prospect. Retrieved 2014-12-04.