MIB Designer supports UTF character sets, because it is written in Java. You can enable UTF-8, for example, by running MIB Designer with
However, SMI does only allow 7bit-ASCII characters and
- carriage-return (CR)
- line-feed (LF)
- tabulators (e.g. TAB)
for all text enclosed in double quotes (") within a MIB file.
As a consequence, MIB Designer will refuse to compile/edit files with UTF-8 specific characters. Instead it will display an error message and mark the offending charcter in the MIB compiler log and file text.