Ofcom tested audience responses to to political labels, including both slang terms - used to describe Scottish nationalists and unionists respectively - as part of a study into offensive language.
Researchers concluded that “nat” was "unlikely to cause concern in most circumstances", and was categorised as mild by participants.
“Yoon” meanwhile, was rated as moderately offensive along with other words like “feminazi”.
Ofcom said it had a "greater potential for offence than mild words" and broadcasters should provide a higher level of context before using it.
Despite the terms’ new categorisations, 60 per cent of participants in the offensive language study had never heard either of them.
Ofcom said that it would take the poll of 600 UK residents, conducted by Ipsos Mori, into account when making judgements about programmes.
But the regulator insisted there was no ban on any of the words on the list.
Broadcasters will instead be asked to consider the words when making programmes in order to avoid causing undue offence.
Adam Baxter, director of standards and audience protection at Ofcom, said: "It's essential that we keep up to date with how viewers and listeners think and feel. Broadcasters' and audiences' right to freedom of expression is important.”
He added: “These findings will help us to strike the right balance between protecting audiences, and children in particular, from unjustified offence, while still allowing broadcasters the creative freedom to reflect real life in their programmes."