Some titles have multiple TMD files. Those are (probably) for different revisions of the title. The TMD file with the larger number in its extension is for the newer revision of the title

Example: for "Brain Age Express Math (USA) (En,Fr,Es)"
-----------------------------------
tmd.512 (newest revision)
tmd.256 (old revision)
tmd.1   (oldest revision)





Missing TMD files
--------------------------------------------
(Title ID == Title Name)

000300045A32454A == Famicom Wars DS - Ushinawareta Hikari (Japan) (3DS Only)
000300044B385545 == Nintendo Fan Network (USA)
000300044B394B4A == Nintendoji (Japan) (3DS Only)
000300045A32414A == Sawaru Made in Wario DL (Japan) (3DS Only)
000300045A324150 == WarioWare - Touched DL (Europe) (3DS Only)
000300045A324154 == WarioWare - Touched DL (USA, Australia) (3DS Only)