Open
Description
Follow up to #31311 (comment)
With #31311 there are advantages to having items in the header list (single instance string).
This is most useful for request headers as they are always constructed strings; whereas response headers set in code are usually and interned string.
Non-exhaustive list of headers not currently included but are interesting:
Commonly used request headers:
public static readonly string XCorrelationId = "X-Correlation-ID";
public static readonly string XRequestId = "X-Request-ID";
public static readonly string XForwardedFor = "X-Forwarded-For";
public static readonly string XForwardedHost = "X-Forwarded-Host";
public static readonly string XForwardedProto = "X-Forwarded-Proto";However if the server is also reverse-proxying/forwarding/routing between other servers; then response headers also become constructed strings (as they are parsed from the network). So that would then potentially include:
// Security header
public static readonly string ReferrerPolicy = "Referrer-Policy";
// Allow the browser to read cross origin timing values for the Resource Timing API
public static readonly string TimingAllowOrigin = "Timing-Allow-Origin";
// Ye olde "ASP.NET" header
public static readonly string XPoweredBy = "X-Powered-By";Location is used for redirect; but sometimes Refresh is also used as a non-JS delay timed redirect (with interstitial)
public static readonly string Refresh = "Refresh";Never seen; but rfc7240
public static readonly string Prefer = "Prefer";
public static readonly string PreferenceApplied = "Preference-Applied";