Source SDK: Mastering the Source/Edit Menu
The Edit Menu on the Control Bar houses a variety of useful tools that can assist you in creating your map.
Undo(CTRL+Z) edit
This button undos any action or edit you've made to anything in your level. The undo button has a limit.
Redo(CTRL+Y) edit
This button gives you the opportunity to redo an undo. The Redo button has a limit.
Toggle Undo/Redo edit
This button toggles ON and OFF your ability to use the Redo and Undo tools.
Find Entities(Ctrl+Shift+F) edit
This button opens a small search box that allows you to search any entity you have in your level, in case you have misplaced them. (add image of find entity search box)
Replace...(Ctrl+Shift+R) edit
This button opens a small search box that allows you to take any entity in your map and replace it with another. (add image of replace search box)
Cut(Ctrl+X) edit
Cuts a selected brush or entity out of the level and onto your clip board, for it to be pasted.
Copy(Ctrl+C) edit
Copies a selected brush or entity out of the level and onto your clip board, for it to be pasted.
Paste(Ctrl+V) edit
Pastes whatever item you have in your clipboard onto the map. Because the button pastes the item as soon as you click it, making it difficult to aim where you paste it when using the drop down box, so it's smarter to use the hotkey.
Paste Special edit
Delete(Del) edit
Deletes any selected brush or entity within the map.
Clear Selection edit
De-selects any brush or entity you have selected in the map.
Select All edit
Simultaneously selects all brushes and entities in the entire map.
Properties edit
Shows the current properties of a selected entity.