It's caused by incorrect use of templates for Harvard referencing like Template:Harv. Some of those errors are caused by a change in Template:Cite book and similar few months back, when they were changed, so that they don't produce the anchors on default, because it was often causing invalid HTML. (This kind of errors can be fixed by adding the parameter ref=harv to the appropriate citation template.) The other errors are caused by typos or not understanding how Harvard referencing works on WP. And not many people check those errors or know how to fix them (my guess).

I created a (incomplete) list of articles with those errors at http://svick.aspweb.cz/ (details for Mumbai are at http://svick.aspweb.cz/Harv2.aspx/Detail/1933) and a user javascript to show error messages for those errors at http://en.wikipedia.org/wiki/User:Svick/HarvErrors.js.

Svick

On Thu, Apr 8, 2010 at 01:52, jidanni@jidanni.org wrote:

I don't get it. In e.g., http://en.wikipedia.org/wiki/Mumbai there are tons of e.g., <a href="#CITEREFPatelMasselos2003">Patel &amp; Masselos 2003</a> <a href="#CITEREFMehta2004">Mehta 2004</a> <a href="#CITEREFHansen2001">Hansen 2001</a> But no corresponding anchors. One will only get No such anchor: CITEREFHansen2001 in ones browser. What's the deal?