验证码

verification code / CAPTCHA, a type of challenge-response test (computing)

variant of 驗|验[yan4]

to examine / to test / to check

to inspect and verify / experimental verification / to validate (a theory) / to authenticate

to admonish / variant of 證|证[zheng4]

certificate / proof / to prove / to demonstrate / to confirm / variant of 症[zheng4]

weight / number / code / to pile / to stack / classifier for length or distance (yard), happenings etc