diff --git a/runtime/doc/syntax.txt b/runtime/doc/syntax.txt
index f6db8f7..23eed7e 100644
--- a/runtime/doc/syntax.txt
+++ b/runtime/doc/syntax.txt
@@ -2721,7 +2721,14 @@
 prefer that spell checking be disabled in comments in LaTeX files.  To do
 this, put the following in your <.vimrc>: >
       let g:tex_comment_nospell= 1
-<
+The comment lines >
+	% nospell{
+	...
+	% nospell}
+will suppress spell checking between them.  These comment lines spelling
+control are known to be fragile; for example, don't include any of the section
+commands (\part, \chapter, \section, \paragraph, etc) inside nospell blocks
+or interleave environments (such as math) across nospell blocks.
 								*tex-verb*
  Tex: Want Spell Checking in Verbatim Zones?~
 
@@ -2828,6 +2835,7 @@
 following sets of characters: >
 
 	a = accents/ligatures
+	b = bold and italic
 	d = delimiters
 	m = math symbols
 	g = Greek