According to the [Vim FAQ](http://vimhelp.appspot.com/vim_faq.txt.html#faq-20.5) `<C-,>` and `<C-.` cannot be reliably be detected by Vim, making the rotate command unusable on certain terminals. Perhaps alternative keybindings could be suggested which fall within the reliably detected range?
According to the Vim FAQ
<C-,>and<C-.cannot be reliably be detected by Vim, making the rotate command unusable on certain terminals.Perhaps alternative keybindings could be suggested which fall within the reliably detected range?