I really do appreciate your help, Michael. I just need to sit back and determine how I'll proceed from here. There's only so much verbosity I can use with XSLT 1.0 in PHP to translate ITEM3, ITEM5, ITEM2, ITEM4, and ITEM1 to look like this:

[ITEM3], [ITEM5] ([ITEM2]), [ITEM4] [ITEM1]

I can, of course, just pop in the values. But I'd like to accommodate for missing data if it exists instead of ending up with something that looks like this:

[ITEM3], (), [ITEM4]

Any one of these values could be missing and I do not have control over the XML data structure or how much data is filled in.