If you want to put some special system-symbols (like Button icons) in your Comment, here's how:

All you need is HxD or some other Hex editor, and of course, FTP on your ps3.






1. Using your FTP server, navigate to /dev_hdd0/home/000000000x (replace x with account you use)/friendim
Transfer your mecomment.dat file to your local disk using your preferred FTP client.

2. Open it with your Hex editor, and choose from this array of hex chars to put in:

EF A2 92 - PS button (untextured)
EF A3 BD - Black Cross (no background) (UPDATE: Lame because this is accessible via the symbols menu in the On Screen Keyboard on PS3)
EF A2 83 - Triangle (untextured)
EF A2 8F - Start button (untextured)

3. Save and upload it to your ps3, overwriting the old one, then exit FTP server and logout of your PS3 user account and log back in.

4. You should see the symbol in your comment.

Notice what I said, that these are all untextured for some reason, so for example, it'll be hard to see that the Start button does indeed say Start, and it'll be hard to see that there is actually a triangle there because the green part only shows up as a lighter gray.

There are probably a lot more of these. All I did to find the few I found was I used the Rcomage RCO dumper on some of the resource files in PS3's dev_flash, most notably explore_plugin_full.rco, system_plugin.rco, and xmb_ingame.rco. Once you dump these, go into the folder you dump the contents into and go to the Text folder, and open English.xml in your hex/text editor of choice. You'll find special chars where they make sense (mostly near button prompts, for example, the "[TRIANGLE]: Options" prompt that appears in the bottom right corner when you hover over someone's PSN id in the Friends category of the XMB. I'm assuming if you keep going through and dumping these files you'll probably find more special chars to insert