Given this plist:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
        <key>hex</key>
        <array>
                <integer>0x0100000c</integer>
        </array>
        <key>oct</key>
        <array>
                <integer>0123</integer>
        </array>
</dict>
</plist>


``plutil -convert json`` prints:

{"hex":[16777228],"oct":[123]}

That is, hexadecimal values are detected and parsed, but "0" as a prefix for octal values (as in C) is not.