A position marking arrangement for a slidable vehicle seat 10,12. The seat includes a first component 18 which is slidable relative to a fixed, second component 16. The seat component 18 has a datum mark 24 thereon and the fixed seat slide 16 has a surface 22 such that relative movement takes place between the datum mark and the surface when the seat slides. The surface has holes 28 or other means for mounting thereon a marker 30 in a range of different positions, and the seat can be latched in any one of the different positions, with the positions being marked by one or more markers 30.