clarify the documentation of the xxx2 output formats: #944 (comment)

Author: yihui

R/html.R

@@ -97,10 +97,10 @@ tufte_html_book = function(...) {
 #' These are simple wrappers of the output format functions like
 #' \code{rmarkdown::\link{html_document}()}, and they added the capability of
 #' numbering figures/tables/equations/theorems and cross-referencing them. See
-#' References for the syntax. Note you can also cross-reference sections by
-#' their ID's using the same syntax when sections are numbered. In case you want
-#' to enable cross reference in other formats, use \code{markdown_document2} with
-#' \code{base_format} argument.
+#' \sQuote{References} for the syntax. Note you can also cross-reference
+#' sections by their ID's using the same syntax when sections are numbered. In
+#' case you want to enable cross reference in other formats, use
+#' \code{markdown_document2} with \code{base_format} argument.
 #' @param ...,fig_caption,md_extensions,pandoc_args Arguments to be passed to a
 #'   specific output format function. For a function \code{foo2()}, its
 #'   arguments are passed to \code{foo()}, e.g. \code{...} of
@@ -114,10 +114,11 @@ tufte_html_book = function(...) {
 #' @inheritParams pdf_book
 #' @return An R Markdown output format object to be passed to
 #'   \code{rmarkdown::\link{render}()}.
-#' @note These function are expected to work with a single R Markdown document
-#'   instead of multiple documents of a book, so they are to be passed to
-#'   \code{rmarkdown::render()} instead of \code{bookdown::render_book()}. The
-#'   functions \samp{tufte_*()} are wrappers of funtions in the \pkg{tufte}
+#' @note These output formats are used to generate single output files, such as
+#'   a single HTML output file (unlike \code{gitbook}, which generates multiple
+#'   HTML output files by default).
+#'
+#'   The functions \samp{tufte_*()} are wrappers of functions in the \pkg{tufte}
 #'   package.
 #' @references \url{https://bookdown.org/yihui/bookdown/}
 #' @export