HTTP头字段在http://www.iana.org/assignments/message-headers/维护的“消息头”注册表中注册。
本文档定义了下列HTTP头字段,所以“永久消息标题字段名称”注册表已经被更新(参阅BCP90)。
+-------------------+----------+----------+---------------+
| Header Field Name | Protocol | Status | Reference |
+-------------------+----------+----------+---------------+
| Connection | http | standard | Section 6.1 |
| Content-Length | http | standard | Section 3.3.2 |
| Host | http | standard | Section 5.4 |
| TE | http | standard | Section 4.3 |
| Trailer | http | standard | Section 4.4 |
| Transfer-Encoding | http | standard | Section 3.3.1 |
| Upgrade | http | standard | Section 6.7 |
| Via | http | standard | Section 5.7.1 |
+-------------------+----------+----------+---------------+
还有,头字段名“Close”已经被注册用于“保留”,因为使用这个名字作为HTTP头字段可能与Connection头字段(6.1节)的“close”连接选项冲突。
+-------------------+----------+----------+-------------+
| Header Field Name | Protocol | Status | Reference |
+-------------------+----------+----------+-------------+
| Close | http | reserved | Section 8.1 |
+-------------------+----------+----------+-------------+
变更控制者是:“IETF(iesg@ietf.org) - 互联网工程任务组”。