White List
To always allow popup windows from a specified domain, you can add it to White List. Popup Purger Pro will skip checking the domain in the White List. Please note, it's the domain you are surfing, not the domain of ads. You can add a domain to White List from Internet Explorer context menu.

Add
Manually add a domain which you want popups to be allowed to the White List. Click this button to invoke the input window like below:

Tip
You can use wildcard characters (i.e. '*' and '?') in the domain name. It works
just like the wildcard characters you're using when you want to search files
and/or folders.
Here're some examples help you understanding how it works:
1) '*.microsoft.com' means all popups from website whose domain name ends with
'.microsoft.com' will be allowed, so popups from 'www.microsoft.com' and 'msdn.microsoft.com'
and so on will be allowed.
2) 'www.microsoft.*' means all popups from website whose domain name starts with
'www.microsoft.' will be allowed, so the popups from 'www.microsoft.com' and 'www.microsoft.net'
and so on will be allowed.
3) '???.microsoft.com' means all popups from website whose domain name ends with
'.microsoft.com' and has 3 characters before '.microsoft.com' will be allowed,
so popups from 'www.microsoft.com' and '123.microsoft.com' will be allowed but
popups from 'msdn.microsoft.com' will still be blocked.
Edit
Edit the selected domain name in the White List. Click this button to invoke the input window like below:

Remove
Delete the selected domain(s) in the White List. You can do multiple selection by holding down CTRL or SHIFT key. If no domain is selected or no domain in White List, this button is disabled.
Clear
Delete all domains in the White List. If no domain in White List, this button is disabled.
Browse
Navigate the browser to selected domain. If no domain in White List or multiple domain are selected, this button is disabled.