Supplementary information is part of SA 700
It is additional information which is not required as per. FRF
Difficult to explain whole concept here
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above video will help you understand concept
Supplementary Information Presented with the Financial Statements
In some circumstances, the entity may be required by law, regulation or Standards, or may voluntarily choose, to present together with the financial statements supplementary information that is not required by the applicable financial reporting framework. For example, supplementary information might be presented to enhance a user’s understanding of the applicable financial reporting framework or to provide further explanation of specific financial statement items. Such information is normally presented in either supplementary schedules or as additional notes.
The auditor’s opinion covers supplementary information that cannot be clearly differentiated from the financial statements because of its nature and how it is presented. For example, this would be the case when the notes to the financial statements include an explanation of the extent to which the financial statements comply with another financial reporting framework. The auditor’s opinion would also cover notes or supplementary schedules that are cross-referenced from the financial statements.
Supplementary information that is covered by the auditor’s opinion does not need to be specifically referred to in the introductory paragraph of the auditor’s report when the reference to the notes in the description of the statements that comprise the financial statements in the introductory paragraph is sufficient.
The law or regulation applicable to the entity may not require that the supplementary information be audited, and management may decide not to ask the auditor to include the supplementary information within the scope of the audit of the financial statements.
The auditor’s evaluation whether unaudited supplementary information is presented in a manner that could be construed as being covered by the auditor’s opinion includes, for example, where that information is presented in relation to the financial statements and any audited supplementary information, and whether it is clearly labelled as “unaudited”.