vi: what is verbose mode and when/how do I use it?

Sometimes When I'm using vi I accidentally hit caps lock when I'm in command mode. This apparently puts vi into verbose mode which I'm having trouble finding documentation about how to use. How and when should I use verbose mode?

[snip]
* Start Vim in verbose mode: vim -V. (Describes each file being sourced).

or from the manual page:

[snip]
When 'verbose' is non-zero messages are printed (for debugging, to stderr).