Imperial units commonly used units for length are (li), (tseung/cheung), (tsek/chek), (tsun/chun), (fen/fan) in descending scale order. These units are now rarely used in daily life, the imperial and metric systems being preferred. The imperial equivalents are written with the same basic Chinese characters as the Chinese system. In order to distinguish between the units of the two systems, the units can be prefixed with "Ying" () for the Imperial system and "Wa" () for the Chinese system. In writing, derived characters are often used, with an additional (mouth) radical to the left of the original Chinese character, for writing imperial units.
Imperial pigeon distributed throughout the Pacific. The Pacific ("D. pacifica") and the Micronesian ("D. oceania") imperial pigeons are similar allospecies, while the Polynesian ("D. aurorae") and Marquesan ("D. galeata") imperial pigeons are larger birds with dark plumage. The red-knobbed imperial pigeon ("D. rubricera") and the spice imperial pigeon ("D. myristicivora") are similar but found in Melanesia and New Guinea. c) The "finschii" subgroup of four species which may be New Guinea representatives of "D. aenea" stock; the purple-tailed ("D. rufigaster"), cinnamon-bellied ("D. basilica") and Finsch's imperial pigeons, which all inhabit offshore islands. The shining or rufescent imperial pigeon ("D. chalconota") occupies more