在我看来，RFC 2616并没有规定这一点。

从第4.3节开始:

The presence of a message-body in a request is signaled by the inclusion of a Content-Length or Transfer-Encoding header field in the request's message-headers. A message-body MUST NOT be included in a request if the specification of the request method (section 5.1.1) does not allow sending an entity-body in requests. A server SHOULD read and forward a message-body on any request; if the request method does not include defined semantics for an entity-body, then the message-body SHOULD be ignored when handling the request.

9.7节:

The DELETE method requests that the origin server delete the resource identified by the Request-URI. This method MAY be overridden by human intervention (or other means) on the origin server. The client cannot be guaranteed that the operation has been carried out, even if the status code returned from the origin server indicates that the action has been completed successfully. However, the server SHOULD NOT indicate success unless, at the time the response is given, it intends to delete the resource or move it to an inaccessible location. A successful response SHOULD be 200 (OK) if the response includes an entity describing the status, 202 (Accepted) if the action has not yet been enacted, or 204 (No Content) if the action has been enacted but the response does not include an entity. If the request passes through a cache and the Request-URI identifies one or more currently cached entities, those entries SHOULD be treated as stale. Responses to this method are not cacheable.c

因此，它没有显式地允许或禁止，并且代理可能会删除消息体(尽管它应该读取并转发它)。

值得注意的是，OpenAPI 3.0版本的规范放弃了对带体的DELETE方法的支持:

请看这里和这里的参考资料

这可能会影响将来这些api的实现、文档或使用。

在我看来，RFC 2616并没有规定这一点。

从第4.3节开始:

The presence of a message-body in a request is signaled by the inclusion of a Content-Length or Transfer-Encoding header field in the request's message-headers. A message-body MUST NOT be included in a request if the specification of the request method (section 5.1.1) does not allow sending an entity-body in requests. A server SHOULD read and forward a message-body on any request; if the request method does not include defined semantics for an entity-body, then the message-body SHOULD be ignored when handling the request.

9.7节:

The DELETE method requests that the origin server delete the resource identified by the Request-URI. This method MAY be overridden by human intervention (or other means) on the origin server. The client cannot be guaranteed that the operation has been carried out, even if the status code returned from the origin server indicates that the action has been completed successfully. However, the server SHOULD NOT indicate success unless, at the time the response is given, it intends to delete the resource or move it to an inaccessible location. A successful response SHOULD be 200 (OK) if the response includes an entity describing the status, 202 (Accepted) if the action has not yet been enacted, or 204 (No Content) if the action has been enacted but the response does not include an entity. If the request passes through a cache and the Request-URI identifies one or more currently cached entities, those entries SHOULD be treated as stale. Responses to this method are not cacheable.c

因此，它没有显式地允许或禁止，并且代理可能会删除消息体(尽管它应该读取并转发它)。

也许下面的GitHUb url会帮助你，得到答案。 实际上，应用服务器，如Tomcat, Weblogic拒绝HTTP。带请求有效负载的DELETE调用。所以记住这些东西，我已经在github中添加了例子，请看看

https://github.com/ashish720/spring-examples

有些版本的Tomcat和Jetty似乎会忽略存在的实体体。如果你想要收到它，那就麻烦了。

这个没有定义。

DELETE请求消息中的有效负载没有定义的语义; 在DELETE请求上发送有效负载主体可能会导致一些现有的问题 实现来拒绝请求。 https://www.rfc-editor.org/rfc/rfc7231#page-29