What’s the difference between event properties and profile properties, and how should they be named?
Event properties are names for metrics (e.g. Viewed Product, Placed Order, Checkout Started) that sync from your integration into Klaviyo based on customers' actions on your site. Profile properties are specific characteristics about the profiles in your account that give you insight on how to construct highly targeted marketing campaigns geared towards them.
When naming a custom event property, use action words and choose a title that is not the same as a profile property. If profile properties and event properties have the same name, profile property data will overwrite event property data. That means that, in segments and flows, only the profile property will appear as a filter. Thus, it is best practice to have different names for each property in your account to avoid confusion.