diff --git a/basics.text b/basics.text
index 1ea71b3..cdf9bf6 100644
--- a/basics.text
+++ b/basics.text
@@ -38,7 +38,9 @@ A paragraph is simply one or more consecutive lines of text, separated
by one or more blank lines. (A blank line is any line that looks like
a blank line -- a line containing nothing but spaces or tabs is
considered blank.) Normal paragraphs should not be indented with
-spaces or tabs.
+spaces or tabs. Note that Markdown expands all tabs to spaces using
+tabstops set at 4 spaces apart. It performs this expansion before
+doing anything else.
Markdown offers two styles of headers: *Setext* and *atx*.
Setext-style headers for `
`, `` and `` are created by
diff --git a/syntax.text b/syntax.text
index d31ed5e..8ff9258 100644
--- a/syntax.text
+++ b/syntax.text
@@ -187,6 +187,8 @@ A paragraph is simply one or more consecutive lines of text, separated
by one or more blank lines. (A blank line is any line that looks like a
blank line -- a line containing nothing but spaces or tabs is considered
blank.) Normal paragraphs should not be indented with spaces or tabs.
+Note that Markdown expands all tabs to spaces using tabstops set at 4
+spaces apart. It performs this expansion before doing anything else.
The implication of the "one or more consecutive lines of text" rule is
that Markdown supports "hard-wrapped" text paragraphs. This differs