We are currently working on our second book compiling content from Mi Yodeya. The book uses a document template that's evocative of the site and includes the logo; this was provided to us by Jin for this purpose (in 2013). The book contains all the URLs required by CC-SA.
This question is about the copyright notice. We are currently using the text and links from the site footer, which read (emphasis added):
site design / logo © 2014 stack exchange inc; user contributions licensed under cc by-sa 3.0 with attribution required
The book contains material that is considerably older than 2014, and actually the logo and design (what's explicitly copyrighted there) are also older than 2014. As a technical writer I've always been told by corporate legal departments to use "inclusive" copyright notices that cover all years in which the content changed, e.g. "(C) 2010-2014".
Which copyright formation should we use?
I asked this question in another venue and a community manager asked me to ask it as a question on our meta.
We are hoping to publish very very soon, so by default we'll do whatever we did last year for the haggadah. This question came up this year during proofreading.