| Kind | Value | annotation | ||
| enumeration | 1_strongly concave | |||
| enumeration | 2_strongly concave to concave | |||
| enumeration | 3_concave | |||
| enumeration | 4_concave to straight | |||
| enumeration | 5_straight | |||
| enumeration | 6_straight to convex | |||
| enumeration | 7_convex | |||
| enumeration | 8_convex to strongly convex | |||
| enumeration | 9_strongly convex |