Here’s another one I encountered recently. Anxiety. Books about anxiety can be classed in a couple different places. 152.46 is for anxiety disorders (emotions), while 616.85/22 is for anxiety (mental disorders or illness). In my mind, this is a pretty fine line. I suppose in some cases the distinction may be obvious with a fairly cursory glance, but other times it may require a longer look at the item in hand to determine its true nature. As a solo cataloguer, I usually don’t have that kind of time.