UTF-16 (16-bit Unicode Transformation Format) is a character encoding capable of encoding all 1,112,064 valid code points of Unicode. The encoding is variable-length, as code points are encoded with one or more code units.
The Unicode Standard encodes characters in the range U+0000..U+10FFFF, which amounts to a 21-bit code space. Depending on the encoding form you choose (UTF-8, UTF-16, or UTF-32), each character will then be represented either as a sequence of one to four 8-bit bytes, one or two 16-bit code units, or a single 32-bit code unit.
Can UTF-16 characters be stored in an IDMS database? How can this data be managed in batch applications and ADS online dialogs?
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:
KB000053322 https://comm.support.ca.com/kb/transferring-data-via-tcpip-between-the-mainframe-using-ads-and-other-platforms-that-support-unicode-and-ascii-may-require-the-ability-to-convert-between-these-character-sets-and-ebcdic-this-documents-addresses-ads-for-cobol-refer-to-tec522052/kb000053322 .
If you are interested in implementing international language support, and UTF-16 is just one option being considered, then Knowledge Document KB000043970 may also be helpful. It documents how RHDCCODE pages can be used to translate and store these versions of EBCDIC data. https://comm.support.ca.com/kb/the-ccsid-idms-uses-is-sbcs-ebcdic/kb000043970
Details on using RHDCCODE can be found in Knowledge Document KB000033139, found here: https://comm.support.ca.com/kb/data-fields-in-foreign-languages-are-showing-up-as-asterisks-or-other-nondisplayable-characters/kb000033139