The staff in the Commission’s Division of Economic and Risk Analysis (DERA) recently analyzed custom tags used in eXtensible Business Reporting Language (XBRL) filings submitted by issuers to comply with the rules requiring financial statement information to be reported in XBRL.[1] Our analysis covered XBRL filings submitted in Forms 20-F, 20-F/A, 40-F and 40-F/A for fiscal years 2019 through 2021[2] by filers preparing their reports using International Financial Reporting Standards as issued by the International Accounting Standards Board. The purpose of the analysis was to analyze trends in filers’ use of custom tags[3] in their XBRL financial data for the aforementioned forms during the last three years in two categories: 1) financial statements (F/S) only and 2) F/S and notes.

The Commission’s rules allow filers to create custom tags when the standard taxonomy does not provide an appropriate element to tag the disclosure. While this customization accommodates unique circumstances in a filer’s particular disclosure, the Commission has acknowledged that the use of custom tags could potentially reduce the comparability of inter-company data.[4] Thus, the Commission’s rules specify the limited circumstances under which a filer may create custom tags.[5]

Custom tag rates on only the financial statements saw a modest increase in 2021, but the overall custom tag rates for financial statements and footnotes combined decreased in 2021. This decrease reverses the trend observed since 2017 when the overall custom tag rates steadily increased each year through 2020.

DERA staff intends to continue reviewing filers’ use of XBRL custom tags in their submissions to the Commission. Depending on the results of those efforts, DERA staff may share additional trends, issue guidance, or pursue other actions.

The staff observations DERA staff was published in 2014 on custom tag rates. For the staff’s previous trend analyses on custom tags, see the Trends section. DERA staff welcomes your questions and comments. Please feel free to email us at StructuredData@sec.gov or leave us a voicemail at (202) 551-5494.

[1] Release No. 33-9002 (Jan. 30, 2009), 74 FR 6776 (Feb. 10, 2009) and Release No. 33-10514 (Jun. 28, 2018).

[2] Fiscal years are based on filers’ self-designations. Our analysis includes custom tags of line item tags and excludes tags that are abstract, member, domain, and related to the document and entity. For definitions of abstract, member, and domain, see XBRL glossary. Document and entity tags are largely related to identification of filings and filers including, for example, form type, company name, filer size, and public float.

[3] 17 CFR 232.405(c)(1)(iii).

[4] See pages 104-105 of Release No. 33-9002 (Jan. 30, 2009).

[5] See 17 CFR 232.405(c)(1)(iii)(B) (“An electronic filer must create and use a new special element if and only if an appropriate tag does not exist in the standard list of tags for reasons other than or in addition to an inappropriate standard label.”).

The staff in the Commission’s Division of Economic and Risk Analysis (DERA) recently analyzed custom tags used in eXtensible Business Reporting Language (XBRL) exhibits[1] submitted by issuers to comply with the rules requiring financial statement information to be reported in XBRL.[2] Our analysis covered XBRL exhibits submitted in Forms 20-F, 20-F/A, 40-F and 40-F/A for fiscal years 2018 through 2020[3] by filers preparing their reports using International Financial Reporting Standards as issued by the International Accounting Standards Board.[4] The purpose of the analysis was to analyze trends in filers’ use of custom tags[5] in their XBRL financial data for the aforementioned forms during the last three years in two categories: 1) financial statements (F/S) only and 2) F/S and notes.

The Commission’s rules allow filers to create custom tags when the standard taxonomy does not provide an appropriate element to tag the disclosure. While this customization accommodates unique circumstances in a filer’s particular disclosure, the Commission has acknowledged that the use of custom tags could potentially reduce the comparability of inter-company data.[6] Thus, the Commission’s rules specify the limited circumstances under which a filer may create custom tags.[7]

Custom tag rates saw a modest increase in 2020 both for financial statements only and when combining financial statements and footnotes. This increase continues the trend from 2018 to 2019.

DERA staff intends to continue reviewing filers’ use of XBRL custom tags in their submissions to the Commission. Depending on the results of those efforts, DERA staff may share additional trends, issue guidance, or pursue other actions.

The staff observations DERA staff was published in 2014 on custom tag rates. For the staff’s previous trend analyses on custom tags, see the Trends section. DERA staff welcomes your questions and comments. Please feel free email us at StructuredData@sec.gov or leave us a voicemail at (202) 551-5494.

[1] Includes Inline XBRL exhibits. 97 out of 526 filers that submitted fiscal year 2020 filings used Inline XBRL.

[2] Release No. 33-9002 (Jan. 30, 2009), 74 FR 6776 (Feb. 10, 2009) and Release No. 33-10514 (Jun. 28, 2018).

[3] Fiscal years are based on filers’ self-designations. Our analysis includes custom tags of line item tags and excludes tags that are abstract, text-related, domain member, domain, and document and entity. For definitions of abstract, domain member, and domain, see the XBRL glossary. Document and entity tags are largely related to identification of filings and filers including, for example, form type, company name, filer size, and public float.

[4] On March 1, 2017, the Commission provided notice that the IFRS Taxonomy was available on the Commission’s website. https://www.sec.gov/rules/other/2017/33-10320.pdf

[5] 17 CFR 232.405(c)(1)(iii).

[6] See n. 2. at 104-05.

[7] See 17 CFR 232.405(c)(1)(iii)(B) (“An electronic filer must create and use a new special element if and only if an appropriate tag does not exist in the standard list of tags for reasons other than or in addition to an inappropriate standard label.”).

The staff in the Commission’s Division of Economic and Risk Analysis (DERA) analyzed eXtensible Business Reporting Language (XBRL) financial data[1] submitted by issuers complying with the 2009 Interactive Data rules to file financial statement information in an XBRL format.[2] Our analysis covered XBRL financial data submitted with Forms 20-F, 20-F/A, 40-F and 40-F/A from January 2017 to December 2019[3] by filers preparing their reports using International Financial Reporting Standards as issued by the International Accounting Standards Board.[4] The purpose of the analysis was to analyze trends in filers’ use of custom tags[5] in their XBRL financial data for the aforementioned forms during the last three years in two categories: 1) Financial statements (F/S) only and 2) F/S and notes.

The Commission’s rules allow filers to create custom tags when the standard taxonomy does not provide a tag for the necessary financial element. While this customization accommodates unique circumstances in a filer’s particular disclosure, the Commission has acknowledged that the use of unnecessary customized tags could potentially reduce the comparability of inter-company data.[6]Thus, the Commission’s rules specify the limited circumstances under which a filer may create custom tags.[7]

DERA staff intends to continue reviewing filers’ use of XBRL custom tags in their submissions to the Commission. Depending on the results of those efforts, DERA staff may share additional trends, issue guidance, or pursue other actions.

For the staff’s previous trend analyses on custom tags, see the Trends section. DERA staff welcomes your questions and comments. Please feel free to call us at (202) 551-5494 or email us at StructuredData@sec.gov.

The staff in the Commission’s Division of Economic and Risk Analysis (DERA) analyzed eXtensible Business Reporting Language (XBRL) exhibits [1] submitted by issuers complying with the 2009 Interactive Data rules requiring financial statement information to be filed in an XBRL format.[2] Our analysis covered XBRL exhibits submitted with forms 20-F, 20-F/A, 40-F and 40-F/A from January 2017 to December 2018[3] by filers reporting in International Financial Reporting Standards as issued by the International Accounting Standards Board. [4] The purpose of the analysis was to analyze trends in filers’ use of custom tags in their XBRL exhibits for the aforementioned forms during 2017 and 2018 in two folds: 1) Financial statements (F/S) only and 2) F/S and notes.

The Commission’s rules allow filers to create custom tags when the standard taxonomy does not provide a tag for the necessary financial element. While this customization accommodates unique circumstances in a particular filer’s disclosure, the Commission has acknowledged that the use of unnecessary customized tags could potentially reduce the comparability of data across filers. [5] Thus, the Commission’s rules specify limited circumstances under which a filer may create custom tags. [6]

DERA staff intends to continue reviewing filers’ use of XBRL in their submissions to the Commission. Depending on the results of those efforts, DERA staff may share additional trends, issue guidance, or pursue other actions.

For the staff’s previous trend analyses on custom tags, see the Staff Observations, Guidance, and Trends page. Learn more about the staff’s 2014 observations on custom tag rates.

DERA staff welcomes your questions and comments. Please feel free to email us at StructuredData@sec.gov or call us at (202) 551-5494.

[1] 7 of 860 forms included in the analysis represent Inline XBRL filings as of July 9, 2019.

[2] Release No. 33-9002 (Jan. 30, 2009), 74 FR 6776 (Feb. 10, 2009) (“2009 Rule”).

[3] Our analysis includes custom tags of line items and excludes tags that are abstract, text-related, member, domain, and document and entity. For definitions of abstract, member, and domain, see XBRL glossary. Document and entity tags are largely related to identification and classification of filers and include, among other things, form type, company name, filer size, and public float.

[4] On March 1, 2017, the Commission provided notice that the IFRS Taxonomy was available on the Commission’s website. https://www.sec.gov/rules/other/2017/33-10320.pdf

[5] See 2009 Rule at 104-105.

[6] See 17 CFR 232.405(c)(iii) (B) (“An electronic filer must create and use a new special element if and only if an appropriate tag does not exist in the standard list of tags for reasons other than or in addition to an inappropriate standard label.”).

Custom Tag Rates in IFRS XBRL Exhibits Submitted in 2017 and U.S. GAAP XBRL Exhibits Submitted in 2011 and 2017

The staff in the Commission’s Division of Economic and Risk Analysis (DERA) recently analyzed eXtensible Business Reporting Language (XBRL) exhibits submitted by issuers complying with the 2009 Interactive Data rules to file financial statement information in an XBRL format. Our analysis covered: [1] Our analysis covered:

1. Custom tags in the primary financial statements of XBRL exhibits submitted for Forms 20-F, 20-F/A, 40-F and 40-F/A reporting in International Financial Reporting Standards (IFRS) as issued by the International Accounting Standards Board (IASB) [2] for 2017 and


2. Custom tags in the primary financial statements of XBRL exhibits submitted for Forms 10-K and 10-K/A reporting in U.S. Generally Accepted Accounting Principles (GAAP) for 2011 and 2017.

The custom tags in our analysis covered all non-member and non-abstract elements. The purpose of the analysis was to discern whether IFRS filers, in their first year of required XBRL submissions, were being consistent in their use of custom tags with other filers, or whether their use of custom tags diverged from other filers. In our analysis, the custom tag rate of IFRS filers is higher than that of other filers. IFRS filers had a custom tag rate of 16% in 2017. By comparison, U.S. GAAP filers had a custom tag rate of 9% in 2017. Or as another comparison, in the first year of full compliance by all U.S. GAAP filers, U.S. GAAP filers had a custom tag rate of 11% in 2011.

The Commission’s rules allow filers to create custom tags when the standard taxonomy does not provide a tag for the necessary financial element. While this customization accommodates unique circumstances in a filer’s particular disclosure, the Commission acknowledged that the use of unnecessary customized tags could potentially reduce the comparability of inter-company data. [3] Thus, the Commission’s rules specify the limited circumstances under which a filer may create custom tags. [4]

DERA staff intends to continue to review filers’ use of XBRL in their submissions to the Commission. Depending on the results of those efforts, DERA staff may share additional analysis, issue guidance, or pursue other actions.

The staff observations DERA staff was published on custom tag rates in 2014. Learn more about the previous trend analyses on custom tag rates.

DERA staff welcomes your questions and comments. Please feel free to call us at (202) 551-5494 or email us at StructuredData@sec.gov.

[1] Release No. 33-9002 (Jan. 30, 2009), 74 FR 6776 (Feb. 10, 2009) (“2009 Rule”).

[2] On March 1, 2017, the Commission provided notice that the IFRS Taxonomy was available on the Commission’s website. https://www.sec.gov/rules/other/2017/33-10320.pdf

[3] See 2009 Rule at 104-105.

[4] See 17 CFR 232.405(c)(iii)(B) (“An electronic filer must create and use a new special element if and only if an appropriate tag does not exist in the standard list of tags for reasons other than or in addition to an inappropriate standard label.”).