Cookie Domain allows you to set a specific domain name for perlQ to use when setting cookies. This can be extremely important to prevent a loophole in cookie restrictions for users taking a survey.

If you fail to set this, cookies will simply be set under the domain they are accessed. This means that a user could first complete the survey at www.yourdomain.com and later complete it again at yourdomain.com even if you have cookie restrictions enabled.

To correctly set this field, you need to use at least two periods in the domain name, such as '.yourdomain.com'. This will allow cookies to be sent to the script even if they were set from www.yourdomain.com or a similar other name. Certain extensions, such as .us or .uk will require three periods in the domain name to properly function.