(Fields): Mention POS requirement when narrowing is in effect.

diff --git a/lispref/text.texi b/lispref/text.texi
index 898f33443b5999cf258bdef5c58df5177bc17592..fccc72d3d0b99551ba7b3b8ddf3b1dcdec8d0272 100644 (file)
--- a/lispref/text.texi
+++ b/lispref/text.texi
@@ -3697,7 +3697,8 @@ field nor the following field; the field functions treat it as belonging
 to an empty field whose beginning and end are both at @var{pos}.
 
   In all of these functions, if @var{pos} is omitted or @code{nil}, the
-value of point is used by default.
+value of point is used by default.  If narrowing is in effect, then
+@var{pos} should fall within the accessible portion.  @xref{Narrowing}.
 
 @defun field-beginning &optional pos escape-from-edge limit
 This function returns the beginning of the field specified by @var{pos}.