Wikipedia is our friend <http://en.wikipedia.org/wiki/Flour>
> In some markets, the different available flour varieties are labeled
> according to the ash mass ("mineral content") that remains after a
> sample is incinerated in a laboratory oven (typically at 550C or
> 900C, see international standards ISO 2171 and ICC 104/1). This is
> an easily verified indicator for the fraction of the whole grain
> remains in the flour, because the mineral content of the starchy
> endosperm is much lower than that of the outer parts of the grain.
> Flour made from all parts of the grain (extraction rate: 100%)
> leaves about 2 g ash or more per 100 g dry flour. Plain white flour
> (extraction rate: 50-60%) leaves only about 0.4 g.
Portugal appears to use the French definitions.
Ash Protein US name Germany France Italy
0.4% 9% pastry flour 405 40 00
0.55% 11% all-purpose flour 550 55 0
0.8% 14% high-gluten flour 812 80 1
1% 15% first clear flour 1050 110 2
>1.5% 13% white whole wheat 1600 150 Farina integrale
di grano tenero
> This table is only a rough guideline for converting bread recipes.
> Since flour types are not standardized in many countries, the
> numbers may differ between manufacturers. Note that there is no Type
> 40 French flour. The closest is Type 45.
>
> It is possible to determine ash content from some US manufacturers.
> However, US measurements are based on wheat with a 14% moisture
> content. Thus, a US flour with 0.48% ash would approximate a French
> Type 55. For US bakers of French pastry seeking an equivalent, for
> example, they could look at tables published by King Arthur Flour,
> showing their all-purpose flour is a close equivalent to French Type 55.
King Arthur bread flour is 13% protein, close to tipo 65.
King Arthur Sir Lancelot Unbleached Hi-Gluten Flour is 14.2%, close
to tipo 110.
King Arthur has a variety of special-purpose flours, see
<http://www.kingarthurflour.com/flours/> and scroll to the bottom of the page.
Jeff