There is a responsibility on S4C to sufficiently protect members of the public from including offensive or damaging content within its television service. S4C must also ensure that any content within a programme that may cause offence, including any swearing, words or gestures, is justified by the context.
Ofcom has published a report that summarises current public attitudes towards offensive language (https://www.ofcom.org.uk/about-ofcom/latest/media/...). In order to respond to requests from our producers for guidance, S4C has developed guidelines on the use of offensive Welsh vocabulary in order to reflect the perceptions in Ofcom's report by taking into consideration the Welsh language.
The guideline on S4C's production website specifies a list of words and gestures that may possibly be insulting and careful consideration should be given before including them in any programme. The context should be of paramount importance when deciding on language palatability, and the document notes context factors that should be considered.
Where the context demands special justification to include a specific word or gesture, this should be discussed with the relevant Commissioner in advance, and S4C's approval should be sought before broadcasting the strongest language on every occasion.