In knitr manual,
in theory, the chunk label should be quoted as well, but for the sake of convenience it will be automatically quoted if you did not quote it (e.g.
{r, 2a} will become{r, '2a'})
But with rstudio 1.2.5042 , R 3.5.3, and knitr 1.2.6, {r, 2a} is not considered as chunk in outline(ctrl+shift+o),but {r 2a} will be in outline.
What's the problem? Should I add comma between {r and chunk label?