Outlining

By default all text is displayed in the Code Editor.
It is possible to select a region of code and make it collapsable so it appears under a plus sign (+).
You can then hide or expand the region depending on whether you want to view it or not.

Cutting, Copying and Pasting code retains the outlining information.
If you copy a region that is collapsed, it will be pasted as an expanded region.

(Edit > Outlining)
Code Window Shortcut menu

Toggle Outlining Expansion - Reverses the current hidden or expanded state of the innermost outlining section in which the cursor lies when you are in a nested collapsed section. (Ctrl + M)(Ctrl + M).
Toggle All Outlining -
Stop Outlining - Removes all outlining information from the entire file (Ctrl + M)(Ctrl + P)
Collapse to Definitions - (Ctrl + M)(Ctrl + O).
Start Automatic Outlining -

Hide Selection - (C# only) Available when Automatic Outlining is turned off or Stop Outlining is selected. Collapses the currently selected text.
Stop Hiding Current - (C# only) Available when Automatic Outlining is turned off or Stop Outlining is selected. Removes the outlining information for the currently selected user defined region.
Collapse Block - (C++ only)
Collapse All - (C# only)
Collapse Comment - Appears at the top of the Code Window Shortcut Menu.

#region something 
#endregion