"Decimal fractions may be added to any of the three time elements. However, a fraction may only be added to the lowest order time element in the representation. A decimal mark, either a comma or a dot (without any preference as stated in resolution 10 of the 22nd General Conference CGPM in 2003,^{[[24]|https://en.wikipedia.org/wiki/ISO_8601#cite_note-24]} but with a preference for a comma according to ISO 8601:2004)^{[[25]|https://en.wikipedia.org/wiki/ISO_8601#cite_note-25]} is used as a separator between the time element and its fraction"