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While this error message is accurate, it might confuse participants. So make sure to add a custom message in the “Display” field, pictured in the first image of this section.
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Regex
Regular Expressions (often shortened to Regex) are slightly more complicated than Expressions. For more information on Regex and how to use them, see Regular Expressions / RegEx
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An email validator is a shortcut around writing an expression to require the elements of an email address be included in the response. The email validator requires that the response be one word (no spaces), and that it contain both an @ symbol and a .com, .net, .edu, etc. It does not, however, validate that the email or domain name is active - for instance, entering fake@12345W2H.org will be accepted.
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