Understanding concepts and members in XBRL fact tagging

This article explains what concepts and members are, how they relate to each other, and most importantly how members are used in the Statement of Changes in Equity when tagging iXBRL documents in Tangelo.

What is a concept?

A concept in XBRL refers to the type of fact you are tagging, such as Revenue, Total Assets, or Profit or Loss. In the taxonomy, each concept has a unique technical name and definition.

For a complete and compliant XBRL filing package, it is essential that every row in the primary financial statements containing financial information is tagged with a suitable concept — either a standard taxonomy concept or a custom (extension) concept if no standard concept fits.

When tagging, carefully review each line item in the statement to determine whether a matching IFRS concept exists. If it does not, you must create a custom extension concept that accurately represents the meaning of that line. Each concept you apply defines the nature of the fact (monetary, integer, or text) and ensures your report is machine-readable, consistent, and regulator-ready.

Example concepts:

Each concept defines what the fact is, including:

• Data type (monetary, integer, string, etc.)
• Labels and multilingual support
• References to IFRS standards
• Rules around usage and validation

What is a member?

A member provides dimensional context for a concept. It defines which specific part of a broader category the fact applies to, like a slice of the data.

In most XBRL reports, members can be used to describe things like regions, segments, or entities.
However, in practice, members play their most critical role in the Statement of Changes in Equity, where they define the individual components of equity.

Members in the Statement of Changes in Equity

The Statement of Changes in Equity table is a special case in XBRL tagging. It uses dimensions and members to distinguish between the different components of equity (e.g., Share Capital, Retained Earnings, Revaluation Reserve) and the movements affecting them (e.g., Dividends, Comprehensive Income).

Each column in the SoCE table represents an equity component, which is expressed as a member under the Components of equity dimension.
The values in the rows—such as opening balance, movements, and closing balance—are concepts, but their full meaning comes from the combination of:

• Concept (e.g., ifrs-full_ProfitLossAttributableToOwnersOfParent)

• Member (e.g., RetainedEarningsMember)

• Dimension (e.g., ComponentsOfEquityAxis)

Example:

Tagging members in Tangelo

When tagging the SoCE in Tangelo:

1. Tag the numeric facts in the body of the table using the appropriate concept.

2. Set the correct members in the header cells of the table.

3. Use the taxonomy browser to select the correct standard member for each equity component, or create a custom member if your report requires an extension.

4. Set the XBRL date property to define the Start of the period and End of the period, since equity tags are applied to two rows in the table. The reporting period must be configured in the table row properties to ensure each equity movement is correctly associated with its timeframe.

5. This ensures both the rows (concepts) and columns (members) are tagged, providing the full dimension context for the SoCE.

Summary

• Concepts = What is being reported (e.g., Dividends Paid, Total Comprehensive Income)

• Members = Which component of equity it belongs to (e.g., Retained Earnings, Share Capital)

• In XBRL tagging, members are primarily used to provide dimension context in the Statement of Changes in Equity.

• Correctly tagging both the concepts and members ensures your report accurately reflects equity movements and passes XBRL validation.

Tangelo’s tagging interface supports you by suggesting valid concepts and members, helping you navigate the taxonomy, and validating that the correct dimensional relationships are applied.