the process of systematically removing a field or replacing it with a value in a way that does not preserve the analytic utility of the value, such as replacing a phone number with asterisks or a randomly generated pseudonym.
Masking email addresses involves altering the address to make it understandable to the recipient but confusing to automated harvesting software. For instance, masking could involve writing out the words "at," "dot," and "com" (or other Top-level domain) and separate each segment of the email address with spaces. For example, using this masking technique, the unmasked email address "firstname.lastname@example.org" would appear in its masked version as "johndoe at ftc dot gov."
- NISTIR 8053, at 42.