The katakana syllabary is used primarily for transcription of foreign language words into Japanese and the writing of gairaigo (loan words), as well as to represent onomatopoeias, technical and scientific terms, and the names of plants, animals, and minerals. It is also occasionally used in some words for emphasis, or to ease reading; katakana may be preferred for words becoming buried in the text if they are written under their canonical form in hiragana. Names of Japanese companies, as well as certain Japanese language words such as colloquial terms, are also sometimes written in katakana rather than the other systems. Formerly, female given names were often written in katakana. 
Historically represented the ye syllable, when 𛀀 was used in its place for what is currently represented by エ. In katakana representations of Old and Early Classical Japanese (when e and ye were phonemically distinct, prior to their merger in the mid-Heian period), ye is instead represented by (a Meiji period invention), to avoid confusion with the modern use of エ to represent e.