I'm afraid I don't properly understand MODMERGEATTRIBUTE

I don't really understand how MODMERGEATTRIBUTE is used, and I was wondering if someone would be willing to help walk me through it.

As I understand it, if I want to add a new item in a standard XML file, I use MODMERGEATTRIBUTE to identify the elements which will be added to the main XML file and I enter the name of the element in the name field. So, if I want to say, add a new weapon, I do it like this:

<Weapon MODMERGEATTRIBUTE="weapon" MODMERGE="insert"

Is that right?

When the merging code needs to merge an XML element from a mod's file in to the game's file, it needs to know what XML element in the game's file to merge it with. As the docs say, by default the matching is done using using the tag name, so in this case the code searches for key "Weapon" and finds a number of them, because the game's file has a number of <Weapon> elements, so it doesn't know with what, if any, to do the merge. MODMERGEATTRIBUTE adds the given attribute's content to the key used for matching, so in that case the code will search for an XML element which will give e.g. "Weaponak.47" and there should be at most one to match.

If I have understood you correctly, I can give MODMERGEATTRITUBUTE's value any name, provided it's unique to uniquely identify it. Thank-you!

Not any name, name of an attribute that uniquely identifies it. In 95% of cases it's going to be MODMERGEATTRIBUTE="name" (literally).

Right, so I didn't understand you correctly. My apologies.