Planning to support or take a stand against the NRA? Better make sure you've got the right organization.

While a number of people have made their opinions of the National Rifle Association known in the wake of the Feb. 14 shooting at Marjory Stoneman Douglas High School in Florida, some have mistaken another group for the NRA because it shares the same acronym.

Sen. Tammy Duckworth took to Twitter in February to inform constituents that a $50 donation she received from an employee at the NRA was from the National Restaurant Association and not the National Rifle Association.

@TammyforIL: It is not true that I received a $50 donation from the NRA. I received a donation from an employee of the National RESTAURANT Association, not the National Rifle Association

"Every once in a while this happens," said a National Restaurant Association spokeswoman.

Duckworth, a veteran of the Iraq War and double amputee, became the director of the Illinois Department of Veterans' Affairs in 2006. In 2009, she was appointed to the post of assistant secretary in the U.S. Department of Veterans Affairs by President Barack Obama.

She went on to be elected to Congress in 2012. Four years later, she was elected to the Senate.

Last year, Duckworth signed Sen. Dianne Feinstein's gun control legislation that would ban a range of guns such as the AR-15 and ban bump stocks.

"The senator was never confused about which organization supported her," a spokesman for Tammy for Illinois, the senator's campaign, told CNBC.

@katieduiven: when your accountant asks why you have a charge to the NRA on your work card fun fact it also stands for National Restaurant Association fun fact it also stands for National Restaurant Association

@Jakeduhshiz: Today I learned NRA is also the national restaurant association

@eatz70: Which NRA? The riflle association or the National Restaurant Association?

@Drewby1028: Got a text from Capital One saying I'd made a 15$ payment to the NRA. Called to complain my account had stolen by some right wing Whacko. Turns out it was my 17 year old applying for a yogurt job and had to join the National Restaurant Association. #BrandingFail