According to the Reiki myth the symbols were given to Dr. Usui following his quest and surrender. The second degree has three symbols, which are introduced with the second attunement process. The symbols interact with each practitioner differently based upon their own level of refinement and healing process. In my experience the symbols, like archetypal beings, have their own quirks, gifts, and personalities. Essentially they assist us to focus our rapidly shifting attention and then reward that discipline by opening a gateway into a particular realm of light. They connect us with the Rei intelligence, the Reiki lineage, and the collective group mind of the communion of Reiki masters.
When working with the symbols address them as both gateway and guardian. They serve as the entity at the threshold and the doorway into the realm of light. Treat the symbols as entities who are here to teach, linking us to the realms beyond the tangible. Be respectful, humble, and kind. The symbols can open paths for those who have been attuned to their song. They will also discern ill intent and neutralize malicious energy before the doorway is opened.
There has been much to-do about whether the symbols should be kept secret and guarded. There are many reasons so called occult symbols are kept secret. In times past sacred knowledge may have been cruelly suppressed and a practitioner’s life may have been in danger and so secrecy was practical. Like the Christian fish, some symbols were an insider’s language and way of communicating solidarity and safety. In this age very few Reiki practitioners in the United States are in danger of their life due to their Reiki practice.
Another reason often given that the symbols should be kept secret is they become dilute when passed around too readily. This has more legs in our day and age yet I find the premise questionable as the Christian crucifix has not become more dilute for being readily available to uninitiated eyes. Symbols are living, changing entities. And as such their metaphoric meaning will shift and change with their accessibility. When the yin-yang symbol came to the west it was known more as a trendy and somewhat exotic glyph on bumper stickers than as a sacred Taoist symbol. Yet now it is more known and enriches multi-cultural understanding and helps inform deep truths about nature and balance. So while the yin-yang may seem to have been desecrated by uninitiated eyes it ultimately did its magic and initiated many western acupuncturists, Chinese medicine adherents, and even Reiki masters to its inherently elegant truth.