If you don't remember the key binds you can hit F1 on your keyboard to see the key binds. For question it is Backspace key puts into your backpack you can also go into your settings and change your key binds, but their are some you can not change.
Thank you Geordiboy
I'm glad that it rectified itself and if it happens again could you please provide a screenshot or a video of this issue. This will help for reproducing this issue or any issue that players might have.
You can try this do a trace report to see your connection and ping. This what do for a trace report run admin command prompt and put in tracert rf4game.com hit enter. Let it run and see what is your connection and ping. If it is not very good you try to reset your router and modem and try it again. It is your connection between you and the server that will cause the chat to do that list player with numbers instead of names.
The severs were restart do to technical issue with the patch. They are working on it and you may experience some disconnects. We are sorry for the inconvenience that this may cause you. We thank you for your patience in this issue while this is being resolved.