CAPTCHA security check

To prevent our servers from being abused by spammers as a tool to send spam emails, PDBj's services which require users to validate that they are actual human users and not secretly bots trying to send thousands of emails per second. These services use the so called CAPTCHA check, which is an acronym for Completely Automated Public Turing test to tell Computers and Humans Apart (more information can be found here).

The following services display a CAPTCHA check and require the user to validate themselves:

• Contact page
• Structure navigator (only when supplying the optional email address)

After trying to submit the form, the users will be presented with the CAPTCHA dialogue which looks like the following:

The user is presented with an image which contains eight alphanumerical characters and some distractions in the background to make it more difficult for bots. In case it is also too difficult for a human user, clicking on the "Request new captcha code" button will generate an alternative captcha image. After entering the code (in this case 72QHE4FR (case insensitive)), simply click on the "Check captcha" button to validate yourself. In case the request fails, you will be presented with a new image and requested to try again. Alternatively, the form will be submitted to the server. To cancel the request, simply click on the cancel button.

The cancel button has the following functionality depending on the service:

Service	Cancel button text	Functionality
Contact page	Cancel	Cancels the submission of the form and the user will be shown the contact page (with the user's input content).
Structure navigator	Cancel email notification	Cancels sending the email notification after completing the job. The job itself won't be cancelled and the user will be informed via the job manager notification system.

Within a single session (the session is terminated by reloading or closing the page), users are only required to validate themselves once.