Custom Answering Rules - How to Format Phone Number with Extension

We need to route incoming calls from a particular number with an extension. What is the RingCentral standard for entering in the phone number. This is not only for enabling these rules, but also so that we can keep our data consistent with our SFDC org. I'm having troubling finding documentation on this issue. 

For example, I need to forward a call from (800) 555-1212 Extension 101 to our Sales Queue. How would I enter this number in to route based on the caller ID phone number? Would it be 8005551212#101, or 8085551212.101, or is there another format that we should follow?

Thanks,

James