HTTP参考手册

标题 | Headers

Pragma

PragmaHTTP / 1.0 一般报头是特定于实现的报头可以具有沿着请求-响应链的各种效果。它用于向后兼容 HTTP / 1.1 缓存，而Cache-Control HTTP / 1.1 缓存不存在。

注意：Pragma未指定用于 HTTP 响应，因此不为普通 HTTP / 1.1 的可靠替换Cache-Control首部，虽然它不表现一样Cache-Control: no-cache，如果Cache-Control在请求中省略报头字段。使用Pragma仅适用于 HTTP / 1.0 客户端的向后兼容性。

Header type	General header, but response behavior is not specified and thus implementation-specific.
Forbidden header name	no
CORS-safelisted response-header	yes

句法

Pragma: no-cache

指令

无缓存

和Cache-Control: no-cache一样。在释放缓存副本之前，强制高速缓存将请求提交给原始服务器进行验证。

例子

Pragma: no-cache

产品规格

Specification	Title
RFC 7234, section 5.4: Pragma	Hypertext Transfer Protocol (HTTP/1.1): Caching

浏览器兼容性

Feature	Chrome	Firefox	Edge	Internet Explorer	Opera	Safari
Basic Support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

Feature	Android	Chrome for Android	Edge mobile	Firefox for Android	IE mobile	Opera Android	iOS Safari
Basic Support	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)	(Yes)

请参阅

Cache-Control

Expires

标题 | Headers相关

1.Accept
2.Accept-Charset
3.Accept-Encoding
4.Accept-Language
5.Accept-Ranges
6.Access-Control-Allow-Credentials
7.Access-Control-Allow-Headers
8.Access-Control-Allow-Methods
9.Access-Control-Allow-Origin
10.Access-Control-Expose-Headers
11.Access-Control-Max-Age
12.Access-Control-Request-Headers
13.Access-Control-Request-Method
14.Age
15.Allow
16.Authorization
17.Cache-Control
18.Connection
19.Content-Disposition
20.Content-Encoding
21.Content-Language
22.Content-Length
23.Content-Location
24.Content-Range
25.Content-Type
26.Cookie
27.Cookie2
28.Date
29.DNT
30.ETag
31.Expect
32.Expires
33.Forwarded
34.From
35.Headers
36.Host
37.If-Match
38.If-Modified-Since
39.If-None-Match
40.If-Range
41.If-Unmodified-Since
42.Keep-Alive
43.Large-Allocation
44.Last-Modified
45.Location
46.Origin
47.Proxy-Authenticate
48.Proxy-Authorization
49.Public-Key-Pins
50.Public-Key-Pins-Report-Only
51.Range
52.Referer
53.Referrer-Policy
54.Retry-After
55.Server
56.Set-Cookie
57.Set-Cookie2
58.SourceMap
59.Strict-Transport-Security
60.TE
61.Tk
62.Trailer
63.Transfer-Encoding
64.Upgrade-Insecure-Requests
65.User-Agent
66.User-Agent: Firefox
67.Vary
68.Via
69.Warning
70.WWW-Authenticate
71.X-Content-Type-Options
72.X-DNS-Prefetch-Control
73.X-Forwarded-For
74.X-Forwarded-Host
75.X-Forwarded-Proto
76.X-Frame-Options
77.X-XSS-Protection

HTTP

超文本传输协议（ HTTP，HyperText Transfer Protocol ) 是互联网上应用最为广泛的一种网络协议。所有的 WWW 文件都必须遵守这个标准。

HTTP目录

1.指南 \| Guides
2.指南：基础 \| Guides: Basics
3.CSP
4.标题 \| Headers
5.方法 \| Methods
6.RFC 2616: HTTP/1.1
7.RFC 4918: WebDAV
8.RFC 5023: The Atom Publishing Protocol
9.RFC 7230: Message Syntax and Routing
10.RFC 7231: Semantics and Content
11.RFC 7232: Conditional Requests
12.RFC 7233: Range Requests
13.RFC 7234: Caching
14.RFC 7235: Authentication
15.状态 \| Status
16.HTTP 请求方法
17.HTTP状态码
18.HTTP 响应头信息
19.HTTP 教程