The distinction between ISSAIs (auditing standards) and other pronouncements in IFPP is based on the way the authority of the ISSAIs was defined in 2013 through ISSAI 100 - Fundamental Principles of Public-Sector Auditing.
ISSAI 100 provides that SAIs may choose different ways to implement the ISSAIs. SAIs may either develop auditing standards based on the ISSAIs, adopt national auditing standards that are fully consistent with ISSAI 100 or apply the ISSAIs directly to their full extent in their audits. ISSAI 100 therefore defines how the ISSAIs may be referred to in an audit report in a way that reflects which of these options the SAI has chosen[1]. If, for example, the ISSAIs have been fully applied, the auditor may
1 ISSAI 100, Purpose and Authority of ISSAIs
2 ISSA 100, Paragraph 8
[1] ISSAI 100, Para 9: Audit reports may include a reference to the fact that the standards used were based on or consistent with the ISSAI or ISSAIs relevant to the audit work carried out. Such reference may be made by stating: “We conducted our audit in accordance with (standards), which are based on (or consistent with) Fundamental Auditing Principles (ISSAIs 100-999) of the International Standards of Supreme Audit Institutions”
ISSAI 100, Paragraph 10: When ISSAIs were adopted as authoritative auditing standards, the reference to standards in an audit report may be made as: “We conducted our audit(s) in accordance with the International Standards of Supreme Audit Institutions”. It also further provides an option to specify which ISSAI or range of ISSAIs were considered relevant and state that ‘we conducted our audit in accordance with the International Standards of Supreme Audit Institutions’. ISSAI 100 therefore also defined which parts of the old ‘ISSAI Framework’ that provides the applicable requirements to auditors making such statements in their audit report. When ISSAI 100 was endorsed by INCOSAI in 2013, there were a large number of documents which did not provide requirements that are relevant in this context, but which were nevertheless called ‘ISSAIs’. This has caused confusion within the INTOSAI community as well as among users of SAI audit reports. With the launch of the IFPP, these other documents will no longer be called ISSAIs.