NB (1) If the station operator posted different instructions somewhere such as on qrz.com, I tried to follow those instructions.
NB (2) Some stations have more recently stated that they no longer respond to requests for paper cards. Nevertheless, there was no such indication at the time at which I submitted the request to which no response was received.
I realise that there are many reasons why I might not receive a response to such a direct request, many of which are not the fault of the other station. Nevertheless, reading around the Internet, some stations do seem consistently not to respond to QSL requests -- even some that advertise that they respond to all requests no matter how they are received.
Emphasising that some of these stations may well be blameless -- international mail in particular seems always to be a bit hit-or-miss -- nevertheless here is a list of those stations to whom direct QSLs have been sent, and from whom no reply was received. All the pertinent QSOs were made in 2010, so there has been plenty of time for a card to arrive via any method.
If you are on this list and believe that I have made a mistake (it happens often enough -- keeping track of several thousand QSLs per year is not an error-free process) please let me know and I will investigate further.