Maximum length of dictionary key names

By Gopinath Taget

The same restrictions apply to dictionary keys as to symbol table names: 255 characters or fewer, and they may be alphanumeric, or a dollar symbol ($), underscore (_) or hyphen (-). Use acdbSNValid() to check the validity of a symbol table name.

The length again depends on the sysvar "EXTNAMES". For more details, please refer to the online documentation.