/usr/share/m17n/IBM904.map is in m17n-db 1.6.4-1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 | # Generated from /usr/share/i18n/charmaps/IBM904.gz
0x0000-0x007F 0x0000
0x0080 0x00A2
0x00FD 0x00AC
0x00FE 0x00A6
|