Amazon Elastic Load Balancing (ELB) now supports additional HTTP methods specified in requests from client applications. Previously, ELB restricted the set of supported HTTP methods to those commonly used by conventional web applications.
With an increasing number of applications requiring support for new HTTP extensions, customers have indicated that they would like more control over the HTTP methods used by their applications. ELB will now accept all HTTP methods sent to your applications. Some examples of methods you can use include “PATCH” for Ruby on Rails 4+ applications, and “REPORT” or “MKCALENDAR” for CalDAV applications.
To learn more, visit the Elastic Load Balancing Developer Guide.