Fix SF bug #687655, String formatting conversions misleading

Doc/lib/libstdtypes.tex

@@ -800,7 +800,7 @@ The conversion flag characters are:
 \begin{tableii}{c|l}{character}{Flag}{Meaning}
   \lineii{\#}{The value conversion will use the ``alternate form''
               (where defined below).}
-  \lineii{0}{The conversion will be zero padded.}
+  \lineii{0}{The conversion will be zero padded for numeric values.}
   \lineii{-}{The converted value is left adjusted (overrides
              the \character{0} conversion if both are given).}
   \lineii{{~}}{(a space) A blank should be left before a positive number