sparql comments

http://www.w3.org/TR/2004/WD-rdf-sparql-query-20041012/

*http://www.w3.org/TR/2004/WD-rdf-sparql-query-20041012/#basicpatterns*

*the example is not correct FOAF. *
this is not very wise in a reference.
try using:
<_1> <foaf:mbox> <mailto:alice@work.example>
*the mailto: misses*


On the optional clause:
I would remove the [] syntax completely. It is only distracting to have 
two ways.
the "OPTIONAL ( )" thing looks more like normal SQL and people will 
recognise it
I would abbreviate it with "OPT ()"
it is clearly better to have the optional thing expressed in human 
readable syntax.

greetings
Leo