I need help accessing and adding specific data to a .dif file

Http://tdn.garagegames.com/wiki/DIF/File_Format

Quote:
dummy2 U32 =2 if GameEntities present
numGameEntities U32 number of GameEntities
GameEntitie ItrGameEntity GameEntitie 1
... ItrGameEntity GameEntitie ...

Are the "GameEntities" all of the entities, be they .dif or .dts? I mean, are all the models listed there in the main dif map file?

Exactly what information is stored there? Does it include the names and coordinates of all the entities? Are there any functions I can use to access just the names of the models and their current coordinates?

If there is more than one model on the map, of the same type, is all of its information copied into the .dif file used for the map, or does it just link back to where it defined the measurements of it before?

Is it like:
Define building 1 all data inserted here
Define building 2 ....
etc.

And then...
Put model_type building 1 at XYZ rotation 120degrees
Put model_type building 1 at XYZ rotation whatever
etc. etc.

I'm writing my own map editor since I don't like any of the ones I've tried. Using stuff I've made in years past to speed up the process. I just need to know where to read the information from, and how to write new data to the file.

Where are all the dif editing functions listed at?