This might be, for example, where it is necessary to detail a specific mechanical component for a customised vehicle or an exact colour of paint to match corporate branding.
Gallai hyn ddigwydd, er enghraifft pan fo angen manylu ar gydran fecanyddol benodol ar gyfer cerbyd pwrpasol neu union liw paent i gydweddu â brandio corfforaethol.