The ASCII CCSID is determined dynamically. By default the GetOEMCP function is used to obtain the current OEM code page identifier, for example CCSID 850, for the system.
If the Use OEM code page configuration setting is specified, the GetACP function is used to obtain the current ANSI code page identifier, for example CCSID 1252, for the system.
The identifier might not be unique. For example, there are differences between IBM® CCSID 932 and Microsoft CCSID 932 - the Client daemon maps the Microsoft one to CCSID 943 which is the equivalent one defined in the CRDA Registry. The Microsoft CCSID 1252 might be the pre-euro or post-euro version - the post-euro is mapped to CCSID 5348.