A map of possible out-of band callbacks related to the parent operation. Each value in the map is a Path Item Object that describes a set of requests that may be initiated by the API provider and the expected responses. The key value used to identify the path item object is an expression, evaluated at runtime, that identifies a URL to use for the callback operation.
The Link object represents a possible design-time link for a response. The presence of a link does not guarantee the caller’s ability to successfully invoke it, rather it provides a known relationship and traversal mechanism between responses and other operations.
Describes the operations available on a single path. A Path Item MAY be empty, due to ACL constraints. The path itself is still exposed to the documentation viewer but they will not know which operations and parameters are available.