which uses double brackets to contain single brackets does not render correctly.
-## Two iterations are sometimes needed
-
-Usually the code produced by perltidy on the first pass does not change if it
-is run again, but sometimes a second pass will produce some small additional
-change. This mainly happens if a major style change is made, particularly when
-perltidy is untangling complex ternary statements. Use the iteration parameter
-**-it=2** if it is important that the results be unchanged on subsequent passes,
-but note that this doubles the run time.
-
## Perltidy does not look for here-document targets inside of quoted strings
For example, consider the following script