-The strings used as comment starts are built from
-`comment-start' without trailing spaces and `comment-padding'."
+The strings used as comment starts are built from `comment-start'
+and `comment-padding'; the strings used as comment ends are built
+from `comment-end' and `comment-padding'.
+
+By default, the `comment-start' markers are inserted at the
+current indentation of the region, and comments are terminated on
+each line (even for syntaxes in which newline does not end the
+comment and blank lines do not get comments). This can be
+changed with `comment-style'."