Mask Description
0700 rwx mask for owner
0400 r for owner
0200 w for owner
0100 x for owner
0070 rwx mask for group
0040 r for group
0020 w for group
0010 x for group
0007 rwx mask for other
0004 r for other
0002 w for other
0001 x for other
4000 Set user ID on execution
2000 Set group ID on execution
1000 Save swapped text, even after use