diff --git a/NEWS.md b/NEWS.md
index d1863e24..bd907b8d 100644
--- a/NEWS.md
+++ b/NEWS.md
@@ -26,6 +26,10 @@ where the formatting is also better._
 - Add a "recession bars" section to the `Tips & tricks` vignette.
   (#503 @grantmcdermott)
 
+- Point out more explicitly how the `draw` argument is evaluated within
+  `tinyplot()` and that it thus has access to the local definition to all
+  variables such as `x` and `y` etc. (#507 @zeileis)
+
 ## 0.5.0
 
 ### New features
diff --git a/R/tinyplot.R b/R/tinyplot.R
index 597b8f05..6050985b 100644
--- a/R/tinyplot.R
+++ b/R/tinyplot.R
@@ -303,7 +303,8 @@
 #'   \code{\link[graphics]{abline}} or \code{\link[graphics]{text}}. Note that
 #'   this argument is somewhat experimental and that _no_ internal checking is
 #'   done for correctness; the provided argument is simply captured and
-#'   evaluated as-is. See Examples.
+#'   evaluated as-is within `tinyplot()` and thus has access to the local
+#'   definition of all variables such as `x`, `y`, etc. See Examples.
 #' @param restore.par a logical value indicating whether the
 #'   \code{\link[graphics]{par}} settings prior to calling `tinyplot` should be
 #'   restored on exit. Defaults to FALSE, which makes it possible to add
diff --git a/man/tinyplot.Rd b/man/tinyplot.Rd
index 676ed5e3..503f1579 100644
--- a/man/tinyplot.Rd
+++ b/man/tinyplot.Rd
@@ -452,7 +452,8 @@ elements to each facet of a faceted plot, e.g.
 \code{\link[graphics]{abline}} or \code{\link[graphics]{text}}. Note that
 this argument is somewhat experimental and that \emph{no} internal checking is
 done for correctness; the provided argument is simply captured and
-evaluated as-is. See Examples.}
+evaluated as-is within \code{tinyplot()} and thus has access to the local
+definition of all variables such as \code{x}, \code{y}, etc. See Examples.}
 
 \item{empty}{logical indicating whether the interior plot region should be
 left empty. The default is \code{FALSE}. Setting to \code{TRUE} has a similar effect