The stringprep conversion service prepares a string of Unicode text in order to increase the likelihood that string input and string comparison work in ways that make sense for typical users.

z/OS® support for the Unicode Standard provides String preparation for internationalized string useful for some internet protocols. This feature is based on RFC 3454. (For more information about this RFC, see http://www.ietf.org/rfc/rfc3454.txt)

The String preparation service is called using a stub routine named CUNLSTRP for AMODE (31) or CUN4LSTP for AMODE (64).