I suppose “be kind” is as self-explanatory as "keep it clean." Still, Twitter is much more fun if everyone is kind. If you have a gripe about a company, send it to them in a DM (direct message). Then when they respond, you can tweet that  -“You would not believe how quickly @GreatCompany resolved an issue for me! Thank you @GreatCompany :)” 

me on Twitter: Finch93