yaimapitu - 11:54 pm on Aug 10, 2013 (gmt 0)
Thanks for the comments.
Those pages that Bing and others keep requesting (mostly Bing, the others do it rather infrequently) belong to various "first versions" of websites that I had just created from scratch (the associated domain names are recent new registrations that have never been used before). I had changed those page names within a few days and provided 301 redirects. So there is no equity and there are no legitimate links to those page names.
There are, of course, certain domain information services who monitor the reports coming from the registrars and start scouring new sites within a day of them being registered (and Google, in their near infinite wisdom, even places those services ahead of the associated sites themselves in the search results!), but to my knowledge those services to not provide links to individual pages, just the domain roots.
My next research will be to explicitly disallow all those old pages in robots.txt and see whether that makes a difference to Bing. :)