A hat tip is an act of tipping or (especially in British English) doffing one's hat as a cultural expression of recognition, respect, gratitude, greeting, or simple salutation and acknowledgement between two persons.
In the modern use of the hat tip the nod has replaced the tip as a manner of respect if one man gives another the nod he should return in kind with either the casual nod up or the formal nod down. In Western societies of the 19th and early 20th centuries, a hat tip was a common non-verbal greeting between friends or acquaintances while walking on a sidewalk or meeting at a social gathering. Typically, two men (female hat tipping was rare) would lift or tip their hats to each other, rather than exchange words of greeting. Where the ritual was used to emphasize social distance, the subordinate was obliged to make the more elaborate gesture, for example fully removing his hat while the superior merely touched his. The military hand salute is thought to have originated as a stylized hat tip; while the civilian may return a salute via a hat tip.
Erving Goffman emphasized the role of hat-tipping as a means of closing encounters between male and female, and restoring both parties thereby to a state of civil inattention. He also suggested that the hat tip was used for greeting a stranger, whereas the equivalent greeting for an acquaintance was the bow.
In the 2000s, the term "hat tip" (often abbreviated to "HT" or "h/t") rose to prominence in the blogosphere to acknowledge someone who has made a significant contribution toward an effort, or someone who drew attention to something new or interesting. It is considered good netiquette when sharing a link or news item to give a hat tip to the person from whom you learned of the item. The on-line versions of the Wall Street Journal and the New York Times regularly give hat tips to users who bring ideas for articles to their attention.
In 1929, syndicated cartoonist Jimmy Hatlo started thanking readers who suggested a funny idea for a strip with the phrase "Thanx and a tip of the Hatlo hat to [name]" at the bottom of his comic strip panel They'll Do It Every Time. He continued drawing the hat tip box in the strip until his death in 1963.
See also 
- Oretha D. Swartz, Service Etiquett (1988) p. 473
- Erving Goffman, Relations in Public (1972) p. 121
- Goffman, p. 121n
- Desmond Morris, The Naked Ape Trilogy (1994) p. 110
- Desmond Morris, Manwatching (1987) p. 144
Further reading 
Emily Post, Etiquette (1937)
J. Willeblood, The Polite World (1973)
|Wikimedia Commons has media related to: Hat tipping|
- Hat Etiquette for Men by Marian T Hovat, traditioninaction.org
- How to tip your hat to someone at Wikihow.com
- An example of a Wall Street Journal article with a hat tip noted to a user
- New York Times sports writer Dave Anderson tips his hat to admirable people in sports