谁能解释一下下面的内容错误信息~

http_status_bad_request (400)
the request could not be processed by the server due to invalid syntax.
因为语法不能被服务器处理
http_status_denied (401)
the requested resource requires user authentication.
请求资源命令必须被验证（拒绝访问）
http_status_payment_req (402)
not currently implemented in the http protocol.
没有完全实现http协议
http_status_forbidden (403)
the server understood the request, but is refusing to fulfill it.
服务器理解了请求，但是拒绝完成他
http_status_not_found (404)
the server has not found anything matching the requested uri (uniform resource identifier).
没有找到任何被指定的uri

http_status_bad_method (405)
the http verb used is not allowed.
http动作不被允许
http_status_none_acceptable (406)
no resp acceptable to the client were found.
应答没有被客户接受
http_status_proxy_auth_req (407)
proxy authentication required.
代理必须被验证
http_status_request_timeout (408)
the server timed out waiting for the request.
服务器在等待请求时中止了
http_status_conflict (409)
the request could not be completed due to a c with the current state of the resource. the user should resubmit with more information.
请求不能被完成，问题是资源冲突。用户应该进行调整
http_status_gone (410)
the requested resource is no l available at the server, and no forwarding address is known.
请求的资源在服务器上不再可用，而且没有转发地址
http_status_length_required (411)
the server refuses to accept the request without a defined c length.
服务器拒绝接受没有定义目录大小的请求
http_status_precond_failed (412)
the prec given in or more of the request header fields evaluated to false when it was tested on the server.
当在服务器上测试请求头文件放弃一个或者多个请求的条件
http_status_request_too_large (413)
the server is refusing to process a request because the request entity is larger than the server is willing or able to process.
服务器拒绝处理请求，原因是请求的大小超过服务器能够处理的大小
http_status_uri_too_long (414)
the server is refusing to service the request because the request uri (uniform resource identifier) is l than the server is willing to interpret.
服务器拒绝服务，原因是请求的uri超过了服务器能够揭示的长度
http_status_unsupported_media (415)
the server is refusing to service the request because the entity of the request is in a format not supported by the requested resource for the requested method.
服务器拒绝服务，原因是请求格式不被支持
找了个从400到415的错误解释，后面的没找到。（转贴）

情况不明，是什么时候出现的错误