IEC-P27-1 explained

IEC-P27-1 (or ISO IR-143) is an 8-bit character set developed by the IEC. When combined with the ISO/IEC 646 character set, this includes all characters required to print the symbols defined in IEC 60027-1. FreeDOS calls it code page 65502.^[1]

Notes and References

1. Web site: Cpi/CPIISO/Codepage.TXT at master · FDOS/Cpi . .