A lame is a thing you use to slash or score loaves of bread just before they go into the oven. Those scores help control how and where the bread rises. They are a bit like escape values for steam pressure to be released from the skin of the loaf.
Wire Monkey make fantastic lames and they even have a Real Bread one.
As it so happens, this week is Real Bread week and real bread matters because it is bread made without additives. At Merton, this means bread at its most elemental and traditional — flour, salt and water — is the foundation of all the loaves we make.