* 仕様書

[REFS[
- [1] <http://standards.iso.org/ittf/PubliclyAvailableStandards/c065274_ISO_IEC_23009-1_2014.zip>
]REFS]

[FIG(quote)[
[FIGCAPTION[
[SRC[>>1]]
]FIGCAPTION]

>
,*Key,*Value,*Semantics
,[CODE[period]],[CODE[String]],"[CODE[Period@id]]. If [CODE[period]] parameter is not present, the default value is the ID of the [CODE[Period]] with the earliest ''PeriodStart''."
]FIG]