Please be careful when moving elevation, section & callout tags in Revit. If a user is not paying attention, they could possibly move all of the detail items (lines, detail components, filled regions, etc.) in a view so they are no longer in alignment with the model.
The problem comes when a tag referencing a view is dragged or moved in a direction not perpendicular to view. In these cases Revit moves the linework long with the moved view. For example, if I move a wall section 300mm away from a wall using the move command, the detail items in that view will seem to move the same 300mm away from the model.
Moving a wall section parallel to the view...
...can cause detail items in that view to move as well
A single click on a tag will provide you with little blue hotpoints. Think of these hotpoints as your friends. Whenever possible you will want to change the appearance of your view with these hotpoints. This will ensure that no detail items are moved within the view relative to the model. Elevations and sections do not have a hopoint to move them perpendicular to a view, only parallel. Say for instance you need to move a wall section tag further down along a wall. If you use the move command and make sure you stay perpendicular to the view, everything will be peachy. Just be sure never to drag a tag as you can never make sure that you are staying perpendicular.
One closing note. If you ever click on a view tag and don't see any hotpoints show up, check to see if the section has been pinned in place. A simple unpin and you will see all of the options restored.