Function keys have well-established meanings in browsers:

• F1: Help
• F3: Find Next (Shift+F3 Find Previous)
• F4 (some browsers and platforms): Address bar
• F5: Refresh (Ctrl+F5 Refresh invalidating cache)
• F6: Cycle through the address bar, then each frame in the page (Shift+F6 cycle backward)
• F7 (Firefox): Turn on caret so that text can be highlighted for copying using keyboard
• F10: Open browser menu
• F11: Full screen
• F12: Developer tools

Crucible assigns its own functions to some of these keys:

• F1: Previous comment?
• F3: Reply to parent comment?
• F6: Go to next unreviewed file?
• F10: Go to next unreviewed file?

This is highly unexpected, confusing (I lose my position in the review) and disrupting (I inadvertently mark a file as reviewed when I have not actually reviewed it). Please remove these shortcuts and never hijack browser-assigned shortcuts again.