Often there are a number of line items that have the same or very similar meaning in one or more sustainability standards.
Each taxonomy (representing the standard) can define these items itself and then everyone preparing filings against each standard or analysing filings needs to decide if particular line items are equivalent and/or consult a concordance if one is published.
A way of solving this challenge and reducing the burden on stakeholders is for all those standards to use the exact same underlying XBRL concepts in their taxonomies where they can all agree that is reasonable.
By analogy, three different car manufacturers could use the same third party to make bulbs for the cars’ interior lights. Each car manufacturer has their own description and part number for the light bulbs but the underlying bulb socket, bulb shape, bulb materials and bulb connector are the same. The bulb is the same bulb in all three situations but it is labelled and described by each of the car manufacturers in their own way. If not bulbs, then perhaps alloy wheels with each manufacturer putting their particular badge (logo) in the centre of the wheel but otherwise the wheel is the same part.
In XBRL taxonomies, it is possible to arrange the structure such that the same concept can be reused between several taxonomies but with appropriate logos and descriptions applied (labels and references)
Example
Two different taxonomies can share a common energy module (listing the various types of energy, total energy consumed etc.)
Each taxonomy (one made by ACME, the other by XYZZY) contains references to its own official standards but not each others. A fact reported against TotalEnergyConsumed in the ACME taxonomy is comparable against a fact reported against TotalEnergyConsumed in the XYZZY taxonomy because both taxonomies are using the same XBRL concept TotalEnergyConsumed.
One taxonomy using sus-energy:TotalEnergyConsumed contains references to the ACME standard:
Another taxonomy using sus-energy:TotalEnergyConsumed (the same concept) contains references to XYZZY:
