File | Settings | Editor | Code Style for Windows and Linux MPS | Preferences | Editor | Code Style for macOS Ctrl+Alt+S
Prefer longer names: Highlight the longest name in the lookup list for code completion. If disabled, highlight the shortest name.
Name prefix and Name suffix: Specify the prefixes and suffixes to be used when generating suggestions for naming new symbols using the MPS code generation features. For blank fields, the default name suggestions without prefixes or suffixes is used. When you add a prefix value, MPS automatically converts the first letter of the suggested base name to upper case.
For example, if the prefix for a static field is defined as s and the type of the field is Counter, then the suggested static field name will be sCounter.