More on error = TRUE

Fixes #323

rmarkdown.Rmd

@@ -181,10 +181,11 @@ The most important set of options controls if your code block is executed and wh
     plots.
 
 *   `error = TRUE` causes the render to continue even if code returns an error.
-    This is rarely useful for data analysis reports, but it's useful for 
-    teaching so that you can illustrate important errors. The default,
-    `error = FALSE` causes knitting to failure if there is a single error
-    in the document.
+    This is rarely something you'll want to include in the final version
+    of your report, but can be very useful if you need to debug exactly
+    what is going on inside your `.Rmd`. It's also useful if you're teaching R
+    and want to deliberately include an error. The default, `error = FALSE` causes 
+    knitting to failure if there is a single error in the document.
     
 The following table summarises the options: