There are lots of scenarios when this comes up:

- braindead configuaration files. - data files that need some massaging - commenting out code blocks in languages which need a prefix comment delimiter on each line (e.g. python's # or haskell's --) - any time you are doing a series of operations calling functions in a module or from a single class/object and the name changes (e.g. foo.x();, foo.y(); foo.z(); and so on);