Working Faster in Emacs by Reading the "Future"
There are a number of times when using Emacs that a command asks for
an input string—e.g. a search string—and offers an intelligent
default value you can accept simply by hitting RET. That’s
fantastic when the default is exactly what you want, but what about
when it’s almost what you want? Do you really have to manually type
out the whole string? This is Emacs after all!