Not a developer? Go to



This is documentation about a configuration directive, which can be placed within Movable Type’s core configuration file, mt-config.cgi, to customize the behavior of the system.

Users having difficulty getting CAPTCHAs to work within Movable Type should pay special attention to this tag. In order to generate captchas, Movable Type needs access to a number of PNG images that come with MT. These images are found in the mt-static directory. The value of this configuration directive should be set to the absolute path on the filesystem to the images/catcha-source directory in mt-static.


CaptchaSourceImageBase /path/to/mt/mt-static/images/captcha-source