To watch your Ps and Qs stands for and means to pay attention to the details of etiquette.
Mind your manners is another way to say watch your Ps and Qs.
Ps and Qs" is short for "pleases" and "thank-yous", the latter syllables pronounced like the letter "Q".
Another proposal is from the English pubs and taverns of the 17th century: bartenders would keep watch over the pints and quarts consumed by the patrons, telling them to "mind their Ps and Qs".
Watch your Ps and Qs also means to be careful about behaving in a polite or proper way We knew to watch our p's and q's around our aunt.
The date of the coinage of 'mind your Ps and Qs' is uncertain.
There is a citation from Thomas Dekker's play, The Untrussing of the Humorous Poet, 1602, which appears to be the earliest use of the expression: Afinius: ... here's your cloak; I think it rains too.
Mind your Ps and Qs is an English language expression meaning "mind your manners", "mind your language", "be on your best behaviour", "watch what you're doing".
Attempts at explaining the origin of the phrase go back to the mid-19th century.
To “watch your six” means to pay attention to what's behind you.
How many people also use the term as a general warning to pay attention to your entire surroundings.
While the phrase has military origins, it is in regular use in the civilian population.