You're in the Local chat channel.
Hence the [L], which isn't your rank, it's just showing your chat channel.
Type /ch g to get into the global chat channel, which will be marked with [G]
There's also the Trade chat channel, (/ch t) which is for Trading with players, nothing more, this will be shown with [T]
And of course, as you've discovered, local, which will only be read by those around you, within a certain radius.
