For Today Only:
Do not Anger
Do not worry
Be Honest in your Work
Be Compassionate to Yourself and Others
Above is a translation of the five precepts as taught in the system of Reiki. A precept is a code of practice. Usui taught them to support his students on their spiritual path of self-healing – they are the baseline to the complete system. These precepts are the teachings of Usui, the roots to what has become the system of Reiki. If one were to practice the precepts alone, the spiritual journey would be swift and triumphant. Their deceiving simplicity undercuts the struggle that is relentlessly experienced when working with them. Though the precepts may lie at the heart of the teachings, the enormity of this challenge prompted Usui to create other methods to support practitioners: these are the other four elements of the system of Reiki.
Apart from the five precepts found in the Japanese text, this creed of Usui also includes a brief introduction, directions for use and background informationii. The creed is in fact a set of fundamental beliefs and directions guiding practitioners on their spiritual journey.
Source: International House of Reiki