How to modify this symbol

I need to modify the exclamation mark on the title::, where can I modify it?

The symbol itself is set in concrete/config/concrete.php Line 1102:

'title_segment_separator' => ' :: ',

But you should not change the core files. Rather copy the concrete/elements/header_required.php to application/elements and then change the symbol on line 69 of the header_required.php:


Thank you, your answer solved my problem.