Very magic mode treats every character apart from letters, numbers, and underscores as a special character.

You can set very magic mode for a command by prefixing your regex strings with v (for example, /vfoo or :s/vfoo/bar).

Very magic mode is often used when many special characters are to be used. For instance, we used the following example to replace cat hunting mice with mice hunting cat:

:s/(cat) hunting (mice)/2 hunting 1

In very magic mode, this can be rewritten as follows:

:s/v(cat) hunting (mice)/2 hunting 1