(User Defined Units): Mention how to enter optional display string.

doc/misc/ChangeLog

+2008-09-30  Jay Belanger  <jay.p.belanger@gmail.com>
+
+	* calc.texi (User Defined Units): Mention how to enter optional display
+	string.
+
 2008-09-25  Teodor Zlatanov  <tzz@lifelogs.com>
 
 	* message.texi (Sending Variables): Fixed variable documentation to

doc/misc/calc.texi

@@ -27877,7 +27877,11 @@ typing @kbd{u d rod} defines the new unit @samp{rod} to be equivalent to
 16.5 feet.  The unit conversion and simplification commands will now
 treat @code{rod} just like any other unit of length.  You will also be
 prompted for an optional English description of the unit, which will
-appear in the Units Table.
+appear in the Units Table.  If you wish the definition of this unit to
+be displayed in a special way in the Units Table buffer (such as with an
+asterisk to indicate an approximate value), then you can call this
+command with an argument, @kbd{C-u u d}; you will then also be prompted
+for a string that will be used to display the definition.
 @kindex u u
 @pindex calc-undefine-unit

lisp/ChangeLog

+2008-09-30  Jay Belanger  <jay.p.belanger@gmail.com>
+
+	* calc/calc-units.el (math-standard-units): Add entries used to
+	display the the values in the units buffer.
+	(math-build-units-table):  Add entries to the units table to be used
+	to display the values in the units buffer.
+	(math-build-units-table-buffer):  Use the display entry of the units
+	table when non-nil.
+	(calc-define-unit): Add option to enter display value of unit.
+
 2008-09-29  Michael Albinus  <michael.albinus@gmx.de>
 
 	* vc-hooks.el (vc-file-clearprops): Check, that FILE is a string.