Bug/Issue Whisper Command

I'm using the whisper command in RCON (say /w [Name] [Message]) however I can only get it to work with characters without spaces. I've tried using quotes, eliminating spaces, using underscores and url encoding. No dice using any of them. Anyone else have any luck?

This command can be used without RCON inside your chat box by simply using (/w [Name] [Message]).