Viewers of news conferences involving ministers from Northern Ireland's power-sharing administration have noted how not one but two sign language interpreters are involved.

The politicians who have featured most often in the news briefings about the pandemic emergency are the First Minister and DUP leader, Arlene Foster, and the Deputy First Minister, Sinn Féin's Michelle O'Neill.

In the past, language and the provisions for Irish made available in Northern Ireland were a source of tension between the DUP and Sinn Féin.

But the sign language arrangements in place at the Covid-19 news conferences are not to cater for the English-speaking and Irish-speaking communities.

In relation to English, there are two formats in use in Northern Ireland.

They are Irish Sign Language (ISL), the system used south of the border and seen at news conferences hosted by the likes of Taoiseach Leo Varadkar, Minister for Health Simon Harris and Chief Medical Officer Dr Tony Holohan, and British Sign Language (BSL), the system commonly used throughout the UK.

According to a senior Northern Ireland public servant, the two interpreters system is used at the Executive news conferences in an effort to provide information to the widest possible audience.

He believes there is some evidence that Irish Sign Language is more commonly used in rural communities while British Sign Language is more popular in towns and cities.

He said it is not related to other divides.

Irish Sign Language is more closely related to French Sign Language than to British Sign Language.

On its official website, the Northern Ireland Assembly includes two versions of a 10-minute tour of the Assembly, its history and its work – one in ISL and one in BSL.