List - Access

This column shows the ProDOS access permissions for each entry.  The letters are:

d - file may be deleted

n - file may be renamed

b - backup needed

i - file is invisible

w - file may be modified

r - file may be read

DOS 3.3 and CP/M only understand "locked" and "unlocked", which correspond to "r" and "dnwr", respectively.  For Pascal and RDOS disks, all files are effectively "unlocked".