You can usually determine the type of profile in line with the relevant use categories according to BS 6180:2011, or the relevant country standard. Here you can also find the classification and the required rail loads. This probably makes it easier: as a general guide, you should use 0.36kN for internal residential areas, 0.74kN for external residential areas, 1.50kN for busier areas such as sales offices or walkways, and 3.0kN for venues hosting large gatherings of people.