As I possibly will become a more frequent contributor, I'd like (for now ;) one thing to be clarified: the way of writing the ID, the "code" of an item/spell/whatever into the infobox. What already seems to be consistent is the capitalization: I think all codes I've come across where all-capitalized – which is fine by me.
More important is the addition, or not, of the file type, i.e. *.itm, *.spl, etc. (And for these the capitalization again.) Islandking uses to add the suffix, where most articles he hasn't touched don't use them – at least this is how it appears to me.
My proposal: omit the file type! It should be clear by the article itself in case of an item, and for spells/scrolls it's in the infobox title. Also there won't be anything to confuse because all spells have IDs that are different from the corresponding scrolls. Another point for this is the potential use of the code in the console, where it has to be typed without a file type suffix, e.g. when using the command CLUAConsole:CreateItem("code",x) for adding an item.
This isn't handled in the infoboxes' documentations and even isn't consistent in the model pages.
Initially I didn’t capitalize .itm .spl because I thought doing this might make it visual to distinguish the real code which is capital and its type. But I see your point, and as of now I couldn’t think of an opposing case to keep using the file type suffix :-) , except, it helps readers to locate the code in NI more easily... so OK, no file type suffix.
After Islandking found more than one instance of the same code for different file types (see my talk page), and as this possibly will happen even more often in BG3, I withdraw from my proposal of omitting the file type suffix from the code field in the infoboxes.
Instead I suggest to add it always and in lower-cases, opposed to an all upper-case code, e.g. BDMISC47.spl.
As the infobox – and in most cases the article category as well – clearly defines if the displayed code is about an area, a creature, an item or a spell, and as this suffix is never used in the console, which we are linking to, it shouldn't be displayed at all.
For spells and their scrolls, the infobox makes it clear which code is what. They're also (usually) separated by icons – at least in the near future.
I'd still like to see the codes in all uppercase, no matter what NI shows as spelling.