This provides a command and a function. They both can be called with or without a range. In addition, they can be called with or without arguments. Without a range they operate on the current line. There are two supported arguments. They are described below: * arg1 the number to start at. The default is one. This will number your selected lines sequentially. The start can be a number, ., $, or, 'x (like getline). * arg2 Text to append after numbers. The default is a space.