See if this helps.
It's from http://www.ehow.com/info_12206433_avg-approved-files-list.html
Approved File Lists
Lists of approved files are a feature of antivirus and security programs, including AVG's. These lists contain files, programs or locations that the antivirus program with avoid when scanning, and/or that the program with firewall capabilities will allow to run. These lists allow you to specify files that you know to be safe
AVG programs do not necessarily use the terminology "approved files list" or even the common whitelist. However, AVG antivirus does have a feature for a similar function. AVG anti-virus allows you to add files and folders to an exceptions list, which excludes them from antivirus scans. A similar features allows you to add safe programs to the exceptions list of "Potentially Unwanted Programs."
Anti-Virus Approved Files
To add a specific file or a path to a folder to the exceptions list in AVG anti-virus, you must open your AVG application, click "Anti-virus" and select the "Manage Exceptions" button. Here you can delete currently approved files, or add new ones to the list by clicking "Add File" or "Add Path." To exclude a program from scanning by AVG, click "Tools" and select "Advanced Settings." Click the "Potentially Unwanted Programs" link and click to "Add an Exception." Browse to the location of the file or folder that contains it, if you don't know the name of the specific file.
AVG offers an antivirus with firewall solution with its AVG Internet Security and AVG Premium Security programs. Open the main interface and select "Firewall Settings" from the tools menu. Choose your current profile, such as "Small Home or Office" network to expand the available options.