It's a baffling sentence to many people but police are warning that online predators communicate using lingo, slang and acronyms that kids understand.

Most online chat was "usually harmless fun", Australian Federal Police (AFP) commander Helen Schneider said.

"It is important to stress that in most cases it is probably nothing to worry about but having a healthy relationship with your children about their safety online can help you decide if there's an issue," she said.

Honest and open conversations about online chats could "help prevent them falling victim to predators, many who pretend to be children or teens".

Phrases such as Code 9 or P911, which meant there was a parent in the room, were used to keep online conversations private from adults peeking over their child's shoulder, Australian Centre to Counter Child Exploitation (ACCCE) said.

GNRN (get naked right now), GNOC (get naked on camera) and NP4NP (naked pic for naked pic) were allegedly used by online predators to collect child abuse material, according to ACCCE.

Anti-child exploitation officers said codes using numbers were also popular shorthand. 1174 meant "nude club", 143 meant "I love you" and Rule 34 meant that "any topic can be made into pornographic content".

After speaking to a handful of 18-year-olds; to them, the acronyms highlighted by the AFP are obviously predatory.

"The predators would have to explain to the kids what they mean," one said.

The only phrases on the list that the group were familiar with were "POV", "catch a case" and "smash".

Phrases such as NIFOC (naked in front of computer) and 1174 (nude club) caught many of the teens by surprise.

The teens believe these acronyms are not commonly used by youth, rather those trying to adapt to seem young online.

In an interview with 18-year-old Taj Beesley, he detailed the vulnerability of teenagers who are going through puberty.

"It's definitely possible for some kids to fall for these ... some young kids haven't developed that commonsense yet," Beesley said.

"You can warn kids about these things, but at the end of the day some may not remember one specific conversation," he said.

Children could be taught gradually over time how to make their own judgements and decisions with the right guidance, he said.

Maintaining trust was also a crucial step to help teens make educated decisions on messaging.

"If I was over-monitored on technology, just like any teenager - it wouldn't stop me from doing what I was doing, it would make me do it more secretively. Which in-turn would be more unsafe."