Material specific details. To date (13 January 2016) this field has only been used in serial and map records. In the case of serials, it is used to define the way in which the issues have been numbered, or how the numbering pattern might have changed. In the case of current periodicals, obviously it will always be left open:


#405 1(1:1, 1966:1)-
#405 第一輯~
#405 試刊(1977.1), 試刊(1978:1), 1978:2, 總4(1979:1)-

But in the case of dead periodicals, it will be closed:

#405 1(1984:1)-31/32(1992:2/3)
#405 1(1971)-22/23(1972); 新1(1973)-31/32(1976); 季刊1(1977)-48(1988); 年刊1(1989)
#405 第一輯(1982)~第六輯(1986), 總第七期(1987:1)~總第三十期(1992:4)

With maps, field #405 contains the scale:

#405 比例尺 1:875000