Donald Trump's 'Make America Great Again' caps have become synonymous with the 45th President and his 2016 campaign. Since the signature red cap was launched early on in Trump's campaign, a series of spinoff versions have been released, in different colours and styles.
A green cap to mark St Patrick's Day (17 March) seems to have a design flaw in that it contains the wrong type clover. The description for the hat says it has an "embroidered four-leaf clover" on the back.
Twitter users were quick to point out that an Irish shamrock, used as a symbol for St Patrick's Day, is in fact a three-leaf clover.
A shamrock is a young sprig of clover and it is said that Saint Patrick used shamrocks to illustrate the Holy Trinity. As such, it has come to be associated with St Patrick's day. Four-leaf clovers are said to bring good luck and quite rare in the wild.
A US-based marketing strategist called out the error by illustrating the difference between a shamrock and a four-leaf clover. She added: "Don't mess it up, #marketing geeks, for #StPatricksDay."