@Case Insensitive Search: There it is, I’ve often wanted to search words with cse off in “/” search.
If \c appears anywhere in a pattern the whole pattern is assumed to be case insensitive(ignore case). It overrides usual settings like smartcase or ignore case e.g.
/\cname or /name\c
or best option is work with smart case option on :set scs
‘smartcase’ can be set to ignore case when the pattern contains lowercase
letters only.

Take a look at :help ignorecase in vim for more info.
I use the ignorecase and smartcase settings as default, and they work great for me. Any search with an uppercase character becomes a case sensitive search.

:set ic
If the ‘ignorecase’ option is on, the case of normal letters is ignored.

*/\c* */\C*