A normal inline expression: 3.14.
The knitr-style inline expressions are ignored by default: r pi.
An expression that spans multiple lines: 3.14.
When a line has leading spaces that are not meaningful, it should still work: 3.14.
An item.
3.14 (leading spaces are meaningful here)
hi FALSE hi 3.14
hi `{r} pi` (four spaces: this is a plain code block)