There's a hint about Rofi icons:
"rofi supports icons with the syntax "\u0000icon\u00001f", so a suitable window_format with application icon should end with "\u0000icon\u001f".
There, conflicting escape codes are used (\u00001f the first time \u001f the second). Also, it's confusing to use when the actual syntax is {app_icon}. So the fixed hint is:
"rofi supports icons with the syntax "\u0000icon\u001f", so a suitable window_format with application icon should end with "\u0000icon\u001f{app_icon}".
Also, "fuzzel" now supports supports the same syntax in dmenu mode as well if you want to mention that.
Corrected now and I've added a small fuzzel paragraph. Thank you!