Issues with IIS 4 and IIS 5

The internal engine of IIS 4 and IIS 5 is based on Windows code pages, so any items that require processing by the engine will use ACP as a base. As a result, for a Web page to display values as UTF-8, those values will have to be converted from ACP to UTF-8, resulting in some character degradation. Table 15-4 shows the values that are affected.

Table 15-4 Values needing conversion for UTF-8 Web-page usage.

URL	Server.MapPath
PATH_INFO	Server.Transfer
AUTH_USER	Server.URLEncode
LOGON_USER	Server-Side Includes
REMOTE_USER	Global.asa
SCRIPT_NAME	AdRot.dll
APP_POOL_ID	ContRot.dll
APPL_MD_PATH	NextLink.dll
PATH_TRANSLATED	FileSystemObject
SCRIPT_TRANSLATED	Logging Utility
APPL_PHYSICAL_PATH	Page Counter Component
UNMAPPED_REMOTE_USER	Permission Checker Component
Request.Form	Tools Component
Request.QueryString	My Info Component
Server.Execute

Response.Write, entity data, and query-string data are never processed in the core engine and can use any code page (including UTF-8).