Certain facts reported in a financial report may need including in a sustainability report. For example, Revenue, might need to be re-reported and further enables reporting of “Revenue per employee” in the sustainability report.
The meaning of Revenue is as important as its value. The meaning is tied to the taxonomy it is defined in.
Example
In a fictitious sustainability report, the revenue figure is reported against the financial taxonomy (“xii”). This is representative of the real world situation where the revenue is prepared for the financial report and later duplicated in to the sustainability report:

However, the revenue per staff figure is not defined in the financial report but is required as part of the sustainability disclosure. So here it is reported against the sustainability taxonomy (“dsd-example-10”):

Links
Inline Viewer – XBRL International Inc. Sustainability Disclosure