Anyone noticed that the backslash doesn’t show up in posts in the ASCII shrug? \
It’s fine there but before an _ it goes because (I think) that _ is used for italics and this escapes it to stop that. You need to use three backslashes - first two to represent the backslash, and the third to stop the italics working.
If you only put two in you’ll get ¯\(ツ)/¯ which sort of works.