Cutting an index to fit a tight space limitation is never fun. At least, I do not enjoy it.

By cutting, I mean shortening the index beyond what I think the index should be. Editing may lengthen or shorten the index, depending on what needs to be done to make the index its best self, while cutting is simply about removing to fit an external standard. 

Yet, I think cutting an index can still be done well. The final index may not be ideal, but it can still be elegant and appear as a coherent whole. To do this, I have developed a form of triage to guide how I cut. 

The word triage comes from the medical world, and refers to making treatment decisions in situations of insufficient time or resources. In a way, triage is heartbreaking because it means that not everyone will receive treatment or treatment in a timely manner, yet it is effective because it forces the medical personnel to start with the patients for whom they can make the biggest impact.

For an index, my goal is to deliver the best index I can by using the most judicious cuts. Which cuts shorten the most while impacting the quality of the index the least? To do this, here are five strategies and considerations I keep in mind.

1) Identify What Needs to be Kept

This step seems counterintuitive because the goal of cutting, after all, is to remove. Yet I still think it is important that the core entries remain largely intact. I want the reader to still get a broad overview of the book from the index. This means identifying the metatopic entries and supermain headings, which cover the main points of the book. Once I have identified these, I may combine or shorten a few subheadings here and there, but mostly I cut around them.

2) Remove Subheadings

I do not like long strings of undifferentiated locators or mixing subheadings with unruly locators, but I will make exceptions to cut an index as subheadings do take up space. My usual bar for when to add subheadings is six or more locators, but if I need to cut I will raise the bar to say ten locators. I will also remove subheadings for less important entries, as a tradeoff for keeping subheadings for my core entries.

3) Eliminate Multiple Entry Points

One of the hallmarks of a good index is that a reader can find the same information in two or more ways. When I cut, I see multiple entry points as a luxury. My goal is to still have at least one entry point for each piece of information, but I will look for ways to cut out repetition. The main way I do this is to remove double-posts. If information is presented as both a main heading and a subheading, I may choose one or the other. I may also use more cross-references to compensate, if it seems like the cross-reference will take up less space.

4) Raise the Bar for Passing Mentions

Another strategy I use is to raise the bar for what I consider to be passing mentions. I actually start thinking about this before I edit the index. If I create an entry that I think I might be willing to cut, I label it so that it is easy to later find. You may ask, why not just cut if the entry is borderline? I would say that there are degrees of passing mentions, and what may be irrelevant to one person is valuable to another. So I tend to err on being inclusive, while recognizing that I may need to change my standard in order to cut.

5) Be Consistent

Regardless of which strategies I employ, I try to be consistent across the index. If I am cutting an entry from a certain type or level of entry, for example, I try to do the same for all entries of that type or level. I do not want the cuts to appear random or for a reader to say, Why is this entry included but not that? I know that a cut index is full of holes, but at least by being consistent I hope to mask the damage and make it appear that the index was still deliberately and thoughtfully made.

Ultimately, cutting an index is about tradeoffs. What gets to stay and what needs to go? These are not always easy decisions, especially if the cuts occur after careful editing. Still, with some planning, I think a decent index can still emerge. The index may not be great, but it can at least still be okay and still serve the reader as best it can.