Required Codepage Support

While processing an NSPI method, a server associates a codepage with all strings expressed as parameters in the method. The server MUST at a minimum be able to convert string representations between the Unicode codepage CP_WINUNICODE and the TELETEX codepage CP_TELETEX. Clients specify a desired codepage for 8-bit strings in input parameters to server methods. This protocol does not specify conversion rules. However, because the protocol allows for clients to be able to reliably access data that has been so converted, once a server uses an algorithm, it MUST NOT modify its algorithm for converting between string representations in different codepages. Doing so would lead to inconsistent behavior of NSPI methods across multiple NSPI sessions.