THe Romans carried things in folds in Togas, Sashes, and arm 'pouches' worn under their clothing. They wore belts made of cloth which again were folded and used to carry items.There are numerous references to to Roman folders but Romans also knew the small utility knife. As most research articles are behind a pay wall I have no idea about their comments. But almost all sources claim that Romans did not have pockets and how they carried small everyday objects is apparently not well known. So "carried discretely" but where and how, especially as carrying a small fixed blade knife is hardly any less discrete.