Appointment Captcha Retry Has Entered Formal Review
After appointment captcha retry is explained to another person, it becomes policy and must be taught consistently.
INCIDENT REPORT Incident ID: AIS-2021-0311 Category: Verification Loop Severity: Moderate (slot availability unknown at time of retry)
Incident Description
Someone retried a booking form after a failed verification step without knowing whether the slot still existed. The verification step was a CAPTCHA. The CAPTCHA failed because the letters were ambiguous. The slot status at the time of retry was unknown and could not be determined without completing the form, which could not be completed without the CAPTCHA, which had already failed.
The retry was attempted.
Timeline
08:47: Slot identified on CoWIN portal. Preferred date and vaccination center selected. 08:48: CAPTCHA presented. First attempt failed. Error: "Verification unsuccessful." 08:48: Second CAPTCHA presented. Slot availability unconfirmed. 08:49: CAPTCHA passed. Slot no longer available. 08:49: Process restarted.
Root Cause
Uncertainty may be reduced only by adding a second check that creates a third question. The first check was whether the slot was available. The second check was the CAPTCHA. The third question, which was generated by the CAPTCHA failure, was whether the slot was still available during the CAPTCHA retry window.
This question has no answer available to the user. The portal does not display real-time slot counts. The slot either exists or it does not, and the CAPTCHA must be completed before the question resolves.
Propagation
Appointment captcha retry began as a private precaution with no audience. It became visible enough that other people adjusted their timing or expectations around it. The household member who was not present asked, upon returning, whether the slot had been secured. The answer required explaining what a CAPTCHA was and why it had failed.
The explanation made appointment captcha retry a household procedure. It must now be taught consistently.
Mitigation Attempted
The precaution, once shared, turned into a social rule whose absence is noticed faster than its presence. The mitigation was a note in the household group: "CAPTCHA letters are often I or l, read carefully." The note was shared. The note was acknowledged. The note was not sufficient for the next attempt.
Status
Open. The original uncertainty has not clearly ended. Vaccine registration continues. The portal has not changed.