An advanced verification allows you to interactively build verification rules and validate them against a live web document or WPF application.
In order to create custom verification you need to highlight the element and choose Build Step... from the menu:
In the Recorder select Verifications node.
Start by selecting a type of Available Verifications:
When crafting verifications, content is dynamically built against the currently selected element. As selections are made, default values are populated according to values the element contains. For example, choose Content as the verification type and three menu options appear.
Click on the down arrow next to each option to see a list of possible values.