The ad hoc usage of Chinese characters for their phonetic values dates nearly to the introduction of Chinese characters to Japan. Two widespread uses of came out of this. On one front, scholars and monks used kanji characters as translation aids between the lines of Chinese texts. On the other, poets simply used kanji phonetically to write in Japanese. Many different characters were used with the same sound values. This system of characters is called , "alphabet of myriad leaves". The of modern Japanese, and developed as organic simplifications of that were eventually codified. are primarily used today for historical terms – in historical order, these are primarily Sanskrit terms dating from the introduction of Buddhism to Japan, Portuguese terms from the 16th and 17th centuries, and Dutch terms from the 17th, 18th, and 19th centuries. found some use in the Meiji period and in the 20th century, but has largely been superseded by . Sanskrit In Buddhist Japanese, Sanskrit terms used in some chants also derive from but were not called such. These Buddhist texts were translated into Chinese (in a Literary Chinese style) in China long ago. The translation rule for mantras was not to translate the mantra, but instead to represent it phonetically with Chinese characters. For the sutras, they were translated into Chinese Literary Language (). The terms () and (), or "perfection of wisdom" and "fully enlightened", both appear in the Heart Sutra, but are written using . Related concepts ("Japanese-origin" readings) should not be confused with . Whereas are characters used to represent Japanese or borrowed words without regard to the meaning of those characters, are readings, typically words, of Japanese origin that have been officially applied to the borrowed Chinese characters, similar to Latin-Germanic origin synonyms in English. When a native Japanese word is written as a compound by meaning only, and this spelling is established in the language, as in , the word is the semantic variety of , and is known specifically as . Intentional improvised use of irregular kanji spellings (as opposed to spelling mistakes) are known as , and generally require (notational reading characters) to be read properly. Many may have started out as . A loanword example is reading as the English-derived word , or "rival". While standardized use , as in having the suffix in order to inflect as for the past tense, only intended for one-off