The word sacred is often used to explain why some Reiki practitioners do not show their symbols and mantras to those who have not studied the appropriate levels of the system of Reiki. Some Reiki practitioners even believe that the symbols and mantras are secret.
For these reasons, The Reiki Sourcebook uses pseudonyms for the mantras instead. They are CKR, SHK, HSZSN, and DKM. The symbols are listed by their numbers from 1 to 4 as is taught in traditional branches.
In Japan some of the symbols and mantras are of use in the public arena and can be found today in martial arts, Shintô, and some new religions.