Like noted above, "NULL" is a programming concept which represents nothing. If a value (such as a customer's last name) is expected, but not provided (for whatever reason), it may be represented as "NULL" in the database. This is a programming mistake. Code would normally expect "NULL" and account for it. Or, more likely, it was expected that the information which would be populated into those fields would *always* be present, but for whatever reason (e.g. a bug associated with the original data collection), it is not, so the code ended up using "NULL" as the values (converting it to text and somehow ending up with "NULL"). Or there's just a bug with the software that was designed to collect those values. They exist, but something went wrong. And you ended up missing it in your email.