The Read-only Registers


The includes three additional registers called the "read-only" registers.

".
Contains the most-recently inserted text. This is updated each time Vim is in insert mode, and allows (for example) the same text to be pasted into the document multiple times.
"%
Contains the name of the current file, which makes it useful in commands that operate on the entire file.
":
Contains the most recent command that was executed on the command-line. As with the other registers in this section, this can be used to repeat the same multiple times without having to type it in each time.