[ASN.1] question about CHOICE with DEFAULT

[naoki hashimoto]

Hi: I do not understand CHOICE in below definition, (from ISO/WD 14827-2, P.19) Time ::= SEQUENCE { time-Year-qty INTEGER (-32768..32767) OPTIONAL, time-Second-qty INTEGER (0..60) DEFAULT {0}, time-SecondFractions CHOICE { <----- deci-seconds INTEGER (0..9), centi-seconds INTEGER (0..99), milliseconds INTEGER (0..999), ...} DEFAULT {0}, <----- time-Timezone SEQUENCE { } OPTIONAL }. Dose the "DEFAULT {0}" mean default selection is zero, deci-seconds, or default value is zero for all alternatives. If it means default selection, how can I give default value to deci-seconds? If it means common default value for all alternatives, Can I think "DEFAULT {0}" is just for a chice type which has only same type alternatives? That's all. Thank you in advance. Naoki Hashimoto