const a storage class or a type modifier?

[Walter Bright]

Jens Mueller wrote:
> I'm converting a .h to a d module. I'm following the guide on
> http://www.digitalmars.com/d/2.0/htomodule.html
> It says
> "D has const as a storage class, not a type modifier. Hence, just drop
> any const used as a type modifier"
> 
> I do not understand the first sentence nor do I find dropping the const
> right. Why should I drop a const?
> In TDPL const/immutable are type qualifiers. Type qualifier is a
> synonym for type modifier, isn't it? And I know storage classes like
> static/ref. In C you have the type qualifiers const, volatile, and
> restrict and the storage classes auto, register, static, extern. Now
> const in D is a storage class?

const in D1 is a storage class, in D2 it's a type modifier. The web page needs 
updating.