To begin, I want to clarify something specific to the people who have been using AutoCAD Architecture: you do not need to tag an item in order for it to appear in a schedule in Revit Architecture. You can't really just draft a schedule either. But this is not a bad situation to be in. Say, for example, you have a typical door schedule. Wouldn't it be nice to just add a door to the model and have that door automatically show up in the schedule?
Creating material takeoffs
Creating key legends and importing CAD legends
Creating custom tags
Revit allows you to instantly schedule an item based on the fact that we are now using a full database. A door, for example, already ...