To solve the challenge, I created a regex that exactly matches any of the 18 required target strings and nothing else. I used a non‐capturing group (?: … ) with each valid token listed as a literal alternative separated by a pipe. Within each literal I escaped only those metacharacters that would otherwise be interpreted by the regex engine – for example, the plus sign in "08:45:30+02:00" is escaped as \+ and the dollar sign in "$special2Var" is escaped as \$. This produces a pattern that will match only an exact occurrence of one of these strings and no other text.