Snapping to Tentative Points on Elements
Snapping is affected by the Snap Lock settings. There are three basic Snap Lock settings: the snap on/off toggle, the Snap Mode, and the Snap Mode override.
When Snap Lock is on, how a tentative point snaps to an element is set by the active Snap Mode (or the override setting if one is active).
You can set the default Snap Mode via the Locks dialog, the pointer's pop-up menu, or the status bar menu. The Snap Mode (or Snap Mode override) is indicated in the status bar.
Snap Mode Override
During a session, most likely you will use a particular Snap Mode for a majority of operations, but occasionally you want to use a different snap mode. At any time, you can override the active Snap Mode for a single snap by choosing a Snap Mode override. The override mode is effective only for the next operation. After you have snapped a tentative point and accepted with a data point (or Reset), the override is cancelled and the active Snap Mode becomes effective again.