We have only recently become aware that both at TFL and TAFL, we have had a known database bug that did not display .hack subjects, unless you clicked the "Show all subjects in category" link. As a result, we have renamed all .hack subjects to just "hack//whatever" (minus the dot).
All .hack// subjects can now be found under "H", listed as hack// .
I apologize for this error on both networks, and hopefully we can find a workaround so we can eventually list them as they were meant to be listed. In the mean time, please look for them under H. ^^;