\c- case insensitive
\C - case sensitive
\<word\> - match only if it’s a whole
word
\& - match what was search
\(\) - make a group that can be repeated with
\1 or \2 .. or \99999
[0-9] - matches a decimal digit
. - matches another of the last character
\+ - matches one or more
* - matches zero or more
[^a] - match anything but a
:s/old/new/gc replace all (Confirm)