Because your character class
[A-z] matches this symbol.
`, and the English letters.
Actually, it is a common mistake. You should use
[a-zA-Z] instead to only allow English letters.
Here is a visualization from Expresso, showing what the range
[A-z] actually covers:
So, this regex (with
i option) won’t capture your string.
In my opinion, it is always safer to use
Ignorecase option to avoid such an issue and shorten the regex.