Yes I believe you are correct Cainehill. I would be willing to bet that they are simple C strings and therefore shorter lengths may be ok. The reason I say may is that some of the strings are stored as:
"String 1" + '\0' + "String 2" + '\0' + ...
and the problem here is that if, say, we change it as follows:
"New 1" + '\0' + '\0' + '\0' + '\0' + "String 2" + '\0'
Thus we have changed string 1 and maintained the starting address of both strings. However if they are stored in a tightly packed method. The code reads the strings by reading the chars up until the first null character then assumes the next character is the beginning of the next string, instead of reading just two strings it will now read, "New 1", 3 null length strings, then "String 2". I know that Windows stores its string resources in this fashion and variable parameter functions like printf and scanf use strings like this as well.
I'm not sure this is how they do read the strings but I'm hoping you are correct which will make the modification easier.
The other issue is that the optimizing complier has embedded DWORD alignment of the strings. That means that, say, if a null-terminator of a string ends on a non-4 byte boundary it will pad it up to the next boundary. That means the CPU no longer need worry about the last two address bits when incrementing between strings. It also means that any would be hacker has to maintain this padding. Not terribly complicated mind you but still a nuisance. The fact that this padding exists though indicates, at least partly, that the tightly packed method I described above is likely not used or else this padding would disrupt it as well.
On a better note the descriptions themselves seem to be stored in large fixed length strings so that should be quite easy to manipulate... the names of items on the other hand are stored in this other manor. I believe if you look at the modding manual - any description / name that can be changed with it will have a fixed length string and any that cannot be changed will be stored variable length. I suspect this is why the limits of modding are the way they are.
Anyway sorry for rambling Cainehill - you just made me start thinking about the subject and I'm thinking out loud
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