[Therion] Bens Upper Flood Example

[Bruce Mutton]

Stacho wrote, 

"> Grid & Legend
> I'm intrigued by the grid and legend input and map definitions.  Have 
> you done something more refined than that generated with the thconfig 
> export command?
What exactly would you like to receive? Here we have a lot of things in the
TODO list."

Thanks Stacho, your comments appreciated, helps clarify my understanding of
Therion.  

Regarding the above quote, I was more wondering about the names used in the
code from Bens file (copied below).  Why would there be survey or scrap data
associated with Legend and Grid?  Unless Legend and Grid are names of a cave
passage and not the legend and gridlines produced on a finished output? 
Perhaps Ben can elaborate.

   input Legend.th
   input Legend.th2
   
   input Grid.th
   input Grid.th2

   map UF_m0
       Legend_s1
       Grid_s1
   endmap

Or am I completely confused?
Bruce