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Captcha Preferences
This section of the Control Panel allows you to set CAPTCHA preferences for your website.
Server Path to Captcha Folder
The server path (not a URL) to the folder containing your CAPTCHA images. In some cases a simple relative path will work correctly. If you are not sure how to determine your server path please contact your system administrator.
Full URL to Captcha Folder
The full URL to the CAPTCHAs image folder, with a trailing slash.
Use TrueType Font for Captcha?
If your server supports TrueType Fonts, then you can enable this setting. If you receive errors such as Call to undefined function: imagettftext() on your site then your server does not support TrueType Fonts and you should set this to "No".
Add Random Number to Captcha Word
Enabling this setting adds a random three-digit number to the end of the CAPTCHA word. This helps make it more difficult for scripts to be able to guess or brute-force the form submission. By default, ExpressionEngine only has about 1000 words in the CAPTCHA word list so by enabling this setting you add a more randomizing element.
Require captcha with logged-in members?
If you enable this preference, then members who are logged in will need to fill out Captcha information in order to post comments (assuming you've enabled Captcha support for comment posting). If you disable this setting, then members who are logged in can bypass the captcha check.