+However, one should *never* create a vector manually as above, such misbehavior
+is deprecated. The vector helpers set a metatable for the created vectors which
+allows indexing with numbers, calling functions directly on vectors and using
+operators (like `+`). Furthermore, the internal implementation might change in
+the future.
+Old code might still use vectors without metatables, be aware of this!
+
+All these forms of addressing a vector `v` are valid:
+`v[1]`, `v[3]`, `v.x`, `v[1] = 42`, `v.y = 13`
+
+Where `v` is a vector and `foo` stands for any function name, `v:foo(...)` does
+the same as `vector.foo(v, ...)`, apart from deprecated functionality.
+
+The metatable that is used for vectors can be accessed via `vector.metatable`.
+Do not modify it!
+
+All `vector.*` functions allow vectors `{x = X, y = Y, z = Z}` without metatables.
+Returned vectors always have a metatable set.