Nicola Sturgeon has advised Scots to wear face coverings when out in public - but stressed the advice is not mandatory.The First Minister announced the guidance this lunchtime on covering up to prevent the spread of coronavirus.But she stressed the evidence guiding her was "limited and not overwhelming".Ms Sturgeon stressed that face coverings are not a substitute for staying at home.But she insisted there are "some benefits" to be yielded if the coverings are used in crowded shops or on public transport.However, she urged people "not to point the finger at people not doing it".The advice does not refer to medical style masks, but a covering such as a scarf.Holyrood chiefs are recommending the use of such coverings as a precaution but will