To remind you:

#
#          u  g  o           u  g  o           u  g  o
#    0600  rw-------   0400  r--------   0200  -w-------    u - user
#    0660  rw-rw----   0440  r--r-----   0220  -w--w----    g - group
#    0666  rw-rw-rw-   0444  r--r--r--   0222  -w--w--w-    o - others

#
# Note that the default 0600 is the most secure one and should only be changed
# if you need your files for shell scripting or other external applications.