IACS Unified Interpretations (UIs) on various IMO Conventions and Codes are mandatory as per PR 31. In general, IACS UIs related to rule requirements are covered in the IRS Rules. However, there are certain IACS UIs which are not covered by the Rules, mainly on topics not addressed by the Rules or on topics not covered in detail in the Rules. Such UIs, which are not covered in the Rules, are listed here. 

It may be noted that these UIs are also applicable to statutory surveys and certification as appropriate, unless the flag Administration has provided its own written interpretation (also see Part 1 Chapter 1, Section 2.1.4 of the Rules and Regulations for the Construction and Classification of Steel Ships).