Andreas,

vielleicht hilft Dir der folgenden Auszug aus der SQL Reference weiter.

Unicode data
Data that contains characters represented by two or more bytes. Each Unicode graphic string is encoded using either UCS-2 or UTF-16.
UCS-2 is a subset of UTF-16. The CCSID for UCS-2 is 13488. The CCSID for UTF–16is 1200.

NCHAR, NVARCHAR, and NCLOB are synonyms for Unicode graphic
data with a CCSID of 1200.
Schau Dir doch mal die SQL Reference an:
Kapitel 2 --> Data Types --> Character Strings und Character Encoding Schemes

Birgitta