When locking in a chastity device is done remotely it is often the case that the keyholder needs photographic evidence that the locked guy is still locked.
One way is to do it is on cam. But if this is not available an alternative is to require the locked guy to produce a photograph which shows his locked device and some evidence of when the photo was taken.
A Locked Status Verification Code (LSVC) could be what you need.
Here's how it works. The locked guy visits this page and enters the email address of his keyholder. The system then generates an eight-character alphanumeric code (the LSVC).
The system then emails the LSVC to the keyholder and a copy of the email to the locked guy, confirming when it was created.
The locked guy then writes down the LSVC on a piece of paper and includes it in his photo.
The keyholder knows from the email when the LSVC was generated and so how current it is to the photo the locked guy sends him.