Improve the wording.
@@ -226,7 +226,7 @@ The result will be the following table in KGTK format:
| steve | zipcode | 45601 | 2 | work |
| steve | zipcode | 45601 | | cabin |
-### Trimming an Omitted Column
+### Trimming Omitted Columns
Copy `file1.tsv`, sending the output to standard output, giving
a partial list of columns and trimming the remainder:
