Email is a part of modern everyday life - but many of its functions still remain a mystery.
Most people regularly use the CC and BCC fields when composing an email, which copy another recipient into the chain.
But, although many of us use the function almost daily, a viral post shared to X, formerly Twitter, showed that the majority of people are completely unaware of what the letters actually stand for.
'Someone said CC means be careful someone's watching,' joked one user on the social media platform.
'CC is the same as putting everyone in the "to" field and I stand by that,' declared someone else.
Someone else joked: 'CC means witnesses added.'
'It's always a little awkward when you realize you're not as tech-savvy as you thought,' one reflected.
So what do the terms actually mean?
The CC field in an email officially stands for 'Carbon Copy.'
The term dates back to the days of sending mail via post, when senders literally had to use carbon paper when writing to create an exact copy of the letter.
To create a physical duplicate of a letter, a piece of carbon paper was inserted between two sheets of paper.
When you CC an email to someone nowadays, the recipients in both the 'to' field and those CC'd in can see each other's email addresses.
CC is best used to loop someone in on an email containing information they need to know, but doesn't need to be solely addressed to them.
There is also a BCC function, which stands for 'Blind Carbon Copy.'
The recipient added to the BCC field cannot be seen by the person the email was intended for.
The email addresses in the BCC field are completely hidden, and it's used for sending out large emails, such as a company client list, where privacy is important.
Email etiquette is ever-changing, and there are important rules to remember when using it in the workplace.
Last year, a Reddit thread discussed the importance of beginning an email with the right tone.
Reddit users also declared that starting an email solely with someone's name was deemed especially 'rude' and 'passive-aggressive.'
Many people send a greeting to the person they're emailing, with a 'hello' or any other form of pleasantry. But Reddit users say those failing to do so can be perceived as impolite and might even suggest you're angry with the recipient.
'I tend to find it slightly rude if someone starts an email with someone's name and a comma. For example: "John, could I get an update on this? Ben."'
They continued: 'No "Hi" or "Dear" or anything, and also no actual sign-off.
'I often find that if you respond with the same level of abruptness, the person can feel as if you are being rude to them, even though you are essentially matching their energy.
'Is it just me who thinks this? Or do people actually prefer slightly abrupt and to the point?'
A commenter suggested it may be a generational difference, as such emails tend to come from 'senior people in the company.'
'The senior people in my company seem to be more likely to just put whatever they want to say in the bluntest wording possible,' they said.
'No "Hi" or greeting of any kind. No sign-off except "Sent from my iPhone."'
Others revealed that they would find it rude - and that they only open an email without a greeting if they were purposefully trying to convey irritation or anger.
'I would find it rude, yeah. But mainly only cause when I do it, it's 100 percent cause I'm p* off with the person,' one user admitted.