You need to make the name decals (by whatever means you know, or software you have) first... then bind them to the number the ship class uses. For example the CVN classes... in Ship_Names.ini the individual ship names are being stored. There they have the numbers attached, so if the name calls a ship the given number will be assigned, and all the decals attached to that number.
NImitz-class carrier + number 68 = will be displayed as USS Nimitz. You need to create a file name like NimitzName68.tga so when decals.ini calls for decal NimitzName, it will use the 068 file. Now it is your task to put the correct name for the correct file number.
Example
KIEV_82_NAMES.INI
[ship001] Name=Kiev Nation=Soviet Number=075 StartDate=12/28/1975 EndDate=6/30/1993
SovietGrey/decals.ini (skin folder)
[Decal003] MeshName=HULL DecalLevel=2 DecalFacing=LEFT FilenameFormat=SovietNavy/SovietShip/Kiev_name Position=98.0,8.0 Scale=20 DecalMaxLOD=3
This will call for Kiev board No. 075 Kiev_name075.tga
Finally, you have to create the decals.ini entry (Like above), but if you want an aft name placement, you need to use the DecalFacing=REAR (I guess). Proper sizing and positioning will be your final task - trial by error
EDIT: Be careful, as far as I know, a single mesh object can handle 4 pairs of decals max.