[quote user="RayS"][quote user="kwyjibo"]There is no argument that can ever justify it; if a field is not obfuscated, it should never require confirmation. If you want to confirm one visible field, why stop there? Let's confirm everything, or we'll have common typos galore. FAVOURITE FOOD MISMATCH. PLEASE RE-ENTER FAVOURITE FOOD. [/quote]It's easy to mis-type. Puting your favourite food as "Samlon" instead of "Salmon" isn't likely to cause any harm. Typing your address as "rt51we542@hotmail.com" instead of "rt51we524@hotmail.com" will mean they cannot contact you at all. Repetiton in that case is a useful quick check because of the severity of the potential failure. Unlike postal addresses which can have several mistakes in and still end up at the right destination, email addresses are not so amenable to errors. [/quote]In fact, I even had to check three times before I spotted the difference between those hotmail addresses.So yes, it is defendable, because an email field is not the same as a Favourite Food field. Though I've never seen a signup form that asked twice for my preferred username.