In the documentation, in sample template description:
Columns O to S, U:
These are Date fields that are related to various dates associated with your Sample. These dates will be in the format dd/mm/yyyy.
This sentence about the date format is not consistent with what is explained above in the doc:
Date fields (purple): Dates are entered in these fields and must be in the form of the ISO 8601 format: yyyy-mm-dd. All date fields also support entries for hours, minutes, and seconds: 2022-01-01T06:11:54 and 2022-01-01T06:11:54+13:30
how to report a datetime variable when time is never known or is sometimes not known?
I can’t find reference to the data format in the documentation for dd/mm/yyyy. Can you point me to the location? You have a tag for v2-rc2 for this comment. The error may have been fixed in the final v2.0.0. A pdf version is of the documentation is here.
Regardless, the date fields should be in ISO 8601 format.
All date fields use the General missingness set. For example, nr would be reported the case you described: Not reported(nr). A value could have been recorded, however, it was not.
As a general comment, how to report missing or unknown values is describe for each part in the parts [reference] described in the Missing sets. Specifics for validating data are described in the validation documentation.