EDIT

We need two specialized modifier types in the context of character creation:

• Structure modifier
  • defining the region of a certain structure
  • e.g. above/below surface, edge,
• Property modifier
  • defining how the property is measured
  • e.g. length measured with laser

These specialized types are needed because a character, consisting of a structure and a property, with one of these modifiers would be treated as an individual character.

Other modifiers like state modifiers and maybe also stage modifiers might be stored with the values in DescriptionElementBase.modifiers or StateData.modifiers