why?

Check this link first:
http://www.iamsterdam.com/en/amsterdam-partners/i-amsterdam/using-the-brand

or contact Kessels Kramer, the designers of the logo/brand.

The reason I asked was because I wanted to see how they indicated the font Avenir should be used in their identity collateral. Looking at an organization's identity guidelines helps me to better understand why and how a particular font should be used.

Or do you mean the Amsterdam City branding by Thonik?
http://www.thonikbyyou.com/

Pieter

Thank you Peter this is what I was looking for. Thank you angusrshamal for your suggestion also.

That's all fine, but usually these identity guides are not for just anyone to look at and study, they are specifically for other external bureaus that do specific work using that brand (in this case for the city of Amsterdam) - due to corporate restrictions and to avoid brand misuse etc.

but you know, go through to the channels above and see. Maybe you'll get lucky.

I see they have a website that details everything