Abbreviated as TN, turning number is a randomly generated security
code, usually a series of digits, displayed as an image that users may need to
read and copy into a form field in order to submit or
validate a form submission online via a
Web browser. Turing numbers are used to ensure there
is a human user instead of automated (bot) submissions.
Turing numbers are commonly used on
e-commerce Web sites or promotional or contest Web sites
—anywhere there is a need to avoid
automated submissions by bots.
[Image: Example of a turing number as it may appear on a Web-based user
submission form]
