HTTP_VERSION (string constant) is defined wrongly.

[ynkdir]

HTTP_VERSION is defined in Windows.Win32.Networking.HttpServer.Apis.

.field public static literal string HTTP_VERSION = "HTTP/1.0"
.custom instance void [Windows.Win32.winmd]Windows.Win32.Foundation.Metadata.DocumentationAttribute::.ctor(string) = (
	01 00 47 68 74 74 70 73 3a 2f 2f 6c 65 61 72 6e
	2e 6d 69 63 72 6f 73 6f 66 74 2e 63 6f 6d 2f 77
	69 6e 64 6f 77 73 2f 77 69 6e 33 32 2f 61 70 69
	2f 68 74 74 70 2f 6e 73 2d 68 74 74 70 2d 68 74
	74 70 5f 76 65 72 73 69 6f 6e 00 00
)

(DocumentationAttribute point to HTTP_VERSION structure (http.h)).

I think it should be alias of HTTP_VERSIONA or HTTP_VERSIONW defined in Windows.Win32.Networking.WinInet.Apis

.field public static literal string HTTP_VERSIONA = "HTTP/1.0"
.custom instance void [Windows.Win32.winmd]Windows.Win32.Foundation.Metadata.NativeEncodingAttribute::.ctor(string) = (
	01 00 04 61 6e 73 69 00 00
)

.field public static literal string HTTP_VERSIONW = "HTTP/1.0"

These are defined in wininet.h.

#define HTTP_VERSIONA           "HTTP/1.0"
#define HTTP_VERSIONW           L"HTTP/1.0"

#ifdef UNICODE
#define HTTP_VERSION            HTTP_VERSIONW
#else
#define HTTP_VERSION            HTTP_VERSIONA
#endif