At JETPUBS we work with a lot of manuals, and as we do we spot some common mistakes that can easily be avoided. These mistakes slow down the revision process and put an intended meaning at risk of misinterpretation. One mistake that is a pet peeve with many an editor is the omission of the serial comma.
The serial comma, also known as the Oxford comma, separates the penultimate and final items in a list.
Example: Today we will be reviewing information from the FCOM, FCTM, and QRH.
In the above example, and in all sentences, the serial comma precedes the conjunction. This is where people start to get confused, because some mistakenly believe that the conjunction takes the place of the comma, but this is only true in one specific case (when using an ampersand). JETPUBS strongly recommends the usage of the serial comma. Why? To eliminate ambiguity. Take the example sentences below:
- I own every album by the Righteous Brothers, Bill Medley and Bobby Hatfield.
- I own every album by the Righteous Brothers, Bill Medley, and Bobby Hatfield.
Both sentences could be interpreted that you own every album by the group, as well as each album made by the individual artists after the breakup. But the first sentence could also be interpreted as you only have every album by the group, and that you are clarifying who the members of the group are. See the Venn diagram below for an illustration of the difference:
Depending on the situation, your audience may be receiving a message that is very different from what you intended.
Let’s look at a more complicated example:
- Every employee is required to read the ABC, DEF and GHI or JKL.
Notice the lack of a serial comma. How is one to interpret that sentence? It’s clear that everyone should read a copy of the ABC, but are the GHI and JKL interchangeable? Could the combination of the DEF and GHI be substituted for reading the JKL? Is the DEF required reading?
Now look at the second example:
- Every employee is required to read the ABC, DEF, and GHI or JKL.
Now it is clear that the GHI and JKL are interchangeable and the other two are required reading.
When working with technical manuals, one often finds lists and procedures that determine the safe operation of machines and vehicles, so for the sake of clarity, whenever writing be sure to use the serial comma and always consider how grammar affects your meaning. Who knows? A well placed comma could save a life.
– David Frank, JETPUBS Inc.