
`r pq(section_A, "# Section A")`

`r pq(section_A, "This section is only printed if the section_A variable is set to true.")`

`r pq(!section_A, "#### Section A is disabled due to lack of input files.")`


```{r, eval = section_A, echo = F, warning = F, message = F, error = T}
paste("This code chunk is part of section A")
message("messy message")
warning("warny warning")

```