These are soft body corals which do not fit into the other categories reflected in soft corals. This group includes to Stereonephthya, these corals have a variety of needs.
It is important that you research each coral, to understand the needs of the coral specifically. Think about the needs of the coral in this way: Lighting, Flow & Nutrition. Some corals are filter feeders while others must be fed meaty foods. Knowing this in advance will help you make educated decisions on which corals you should or should not add to your tank.