Copyright infringement question

[Carol]

Snape's Witch wrote:
> Since Carol's brought the topic over here, I thought I'd comment also:
> 
> The name Sherlock Holmes is NOT trademarked as evidenced by the 
> numerous unauthorized pastiches (a fancy word for published fanfic!) 
> and deplorable movies.  (There hasn't been a decent Holmes since 
> Jeremy Brett died.)  I definitely know that my favorite, the Mary 
> Russell series by Laurie R. King, is unauthorized.
> 
> As far as the HP series trademarks, using my Chocolate Frog card 
> collection, which covers PS/SS & CoS, as reference, the following 
> names are trademarked: Albus Dumbledore, Minerva McGonagall, Severus 
> Snape, Rubeus Hagrid, Gildroy Lockhart, Voldemort. Why these names 
> were chosen and not Hooch, Pince, etc., is a puzzle! There aren't 
> cards for HRH, but I assume they're also trademarked.

Carol responds:
Very interesting! Can you provide a link to this information?

Also, just for the sake of discussion, could an author mention JK
Rowling in a novel without permission from JKR herself? Obviously, her
name isn't trademarked and she's a public figure, so she can be
discussed in a newspaper or Internet forum, but could an author have a
fictional character claim to have known her and gone to school with
her or some such thing? I'm not talking about a subplot involving her
in a fictional love affair or anything like that. I'm just wondering
if the names of celebrities are protected in any way as the names of
characters (at least copyrighted character names) apparently are.

Carol, who would know what to say if a client tried to include a
subplot about Severus Snape ("You can't do this; sorry!"), but is
still concerned about the fictional mayor of New York in the
manuscript she's editing, who can be specifically identified despite
being unnamed because of the time frame