How do I put % in a format sting?

[John Salerno]

Carsten Haese wrote:

> While I wholeheartedly agree with the sentiment, calling the "?" a
> formatter only blurs the already blurred distinction between string
> formatting and parameter passing. The "?" is a parameter placeholder.

Yeah, you're right. I was actually raising an eyebrow as I typed 
"formatter", because I wasn't sure what to call it. :)