In terms of the full set of CA ADS functions, including auto-editing, translating things to upper case, etc; IDMS does not support anything but EBCDIC related character sets. If there is a desire to implement these features with UTF-16 data, it would be necessary first to translate that data to EBCDIC. That is not something IDMS does automatically. If there is a need or desire to do this, the following document may be helpful, regarding how to translate between EBCDIC & other character sets:
If you are interested in implementing international language support, and UTF-16 is just one option being considered, then Knowledge Document KB 43970 may also be helpful. It documents how RHDCCODE pages can be used to translate and store these versions of EBCDIC data.
Details on using RHDCCODE can be found in Knowledge Document KB 33139