Does anybody know about this grand secret?

Okay. I have been trying to figure this out for the last hour. I need to make a terrain for my game and I have A7. Now I can go into the engine and create a new terrain, but to make it any good I need to move each pixel individually; not very efficient. In the manual there is a single entry which talks about the different tools you can use with terrain that says:

Quote:

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"Move: Moves the selected vertices upwards or downwards with the mouse. The [SS] button activates a soft selection that also moves the adjacent vertices."

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I have checked the entire manual, this entire site, and everywhere else I could possibly think of, and nothing comes up under "SS", "[SS]", "Soft Select", etc. I can't even find a reference to it. Could anybody clue me into this magical tool which will make my terrain making go SO much faster? Thanks!