Physicists have many odd ideas, but one of their oddest surely is dark matter. It is the dense, invisible stuff which fills the universe, but its existence can’t be proven directly, hence the term dark. It also has a sister: dark energy. Dark energy, like dark matter, is also invisible and cannot be directly proven to exist. However, dark energy appears to explain why the universe is not only expanding, but doing so at an accelerated rate.

Scientists are working hard to find out which of these two things is more abundant in the universe. If there is more dark matter than dark energy, then the gravity of the dark matter could eventually cause the universe to stop expanding and then start shrinking, collapsing into a single point, in a very noisy event called a “big crunch”. Alternatively, if there’s more dark energy than dark matter, it could mean that the universe will continue to expand but, like spots on an expanding balloon, everything will be pulled further and further away from each other, resulting in a very cold, lonely universe.

The good news is that either scenario won’t happen for billions of years. The bad news is that in either case, all living things will cease to exist. To paraphrase Einstein, “Bummer.”

Fortunately, the other two qualities of our universe, space and time, don’t have a corresponding “dark” component; that is, there’s no such thing as dark space or dark time, except perhaps on Star Trek. However, there is a corresponding component in our profession, and it is called dark text.

Dark Text Matters

Dark text refers to the many layers of hidden meaning in any text segment. It ranges from the implied meaning that the author intended, or that the reader infers, to much deeper, more hidden meanings.

Here’s a simple example:

To print a document, click Print.

The dark text of this step is:

• a document is a piece of paper
• you’ll need a printer to print something
• “clicking” involves position the cursor on a monitor over a certain graphical element
• the printer must be connected to a computer and must be configured correctly

Darker text could include:

• you should be careful before you print something: once it’s printed, you can’t “undo” it
• the printer must have toner and paper; electricity would also be helpful
• if you can’t figure this out, call your 11-year old relative who knows more than you do about computers

There’s Nothing Funny About Funny Money

Here is a more interesting example. In stores, you often see this sign:

We do not accept $50 or $100 bills.

The first level of dark text is derived from the fact that this statement does not explicitly tell the reader what to do or not do. So the “obvious” (or lighter) dark text is:

Don’t even try to give us $50 or $100 bills.
The next level of dark text is:

We don’t want counterfeit money, which typically is $50 or $100 bills.

However, there is a third level of dark text, which is darker (and more sinister) than these two other levels.

Because we don’t accept $50 or $100 bills, we will accept $5, $10 and $20 bills, even if they are counterfeit.

This, in fact, is exactly what has been reported by the authorities. Counterfeiters know that unless stores are checking every bill they get, they will simply assume the lower denomination bills are legitimate. These stores have inadvertently given a sign to these criminals that they will take their fake money.

What, then, should the sign say, to scare away any potential counterfeiters? Perhaps something like this:

WARNING! We check all paper currency to make sure it is not counterfeit. If you try to use counterfeit money here, you will be caught and prosecuted to the fullest extent of the law. Punishment can include a major fine and imprisonment for up to 14 years.

Note that most of the dark text has been removed. This is what is known as “writing from the user’s perspective”.

As technical writers, we must be aware of dark text, and where possible, try to minimize it. It’s true that we cannot possibly document all of the hidden meaning in text, nor should we. Still, much information may be hidden or very subtle and must be exposed or more clearly stated. To decide when to expose dark text, you need to ask yourself:

Would a typical user need to know this fact in order to more effectively use the thing I am documenting?

The goal is to give users all the information they need to do their jobs, and no more than that. This is an axiom of technical communication, and will be so until the end of the universe.