| Kind | Value | annotation | ||
| enumeration | 1_strongly concave | |||
| enumeration | 2_moderately concave | |||
| enumeration | 3_slightly concave | |||
| enumeration | 4_flat | |||
| enumeration | 5_slightly convex | |||
| enumeration | 6_moderately convex | |||
| enumeration | 7_strongly convex | |||
| enumeration | 8_revolute |