The alphabet of Loglan has two historical versions. In that of 1975[2] there were only 21 letters with their corresponding phonemes. In the final version of 1989[3] five more phonemes had been incorporated: letter H (/h/) was added to the alphabet in 1977 by popular demand; letter Y (/ə/) was added in 1982 to work as a kind of hyphen between the terms of a complex word; letters Q (/θ/), W (/y/) and X (/x/) were added in 1986 in order to allow the incorporation of the Linnaean vocabulary of biology, and they were useful to give more exact pronunciations to many borrowed names.