How to make certain validation rule only fires off upon item creation?

Summary

How to make certain validation rule only fires off upon item creation?

Content

We have a requirement to only trigger a certain item validation rule upon actual item creation (UI item creation, UI item copy, webservice item creation & import batch creation) but not afterwards upon item update (UI item update, webservice item update, import batch update) or item rule set impact analysis.

Question is if this is possible and if so how to achieve this?

 

PS: Solution should be bulletproof, meaning no user-dependent assumptions (eg do not use item copy) or loopholes (read: user cannot bypass)

Version

20C