Regex in search for is not case sensitive

[caballo-blanco]

In "Find files" in "search for" when I use regex ,it's not case sensitive. Also I noticed it is working on particular part between \ \ \ in path.
I do not quite get how it is working, could someone explain it to me because for example I can write "xrp" in regex and it will not search for only xrp file or folder but for Xrp (ant others with capital letters) and in fact for .*[xX][rR][pP].*

[Gral]

Did you read HELP?

Modifiers

Modifiers are used for changing behaviour of regular expressions.

(?i) Ignore Upper-/lowercase. In Total Commander, this is the default for file names.
(?-i) Case-sensitive matching.