If PS Position specified for COPY PRESENTATION SPACE TO STRING is on the second byte of a DBCS character (i.e. the copy begins with the second byte of a DBCS character), the second byte of the DBCS character will be passed as an SBCS space (20H) and no error will be returned. It is the application's responsibility to check and handle the fragmented byte of bisected DBCS characters.
Also, if COPY PRESENTATION SPACE TO STRING ends with the first byte of a DBCS character, the first byte of the DBCS character will be passed as an SBCS space and no error will be returned.