ordering of selected rows from an ordered subselect

Hi,

we know that rows in a table are not stored in any particular order
and explicit order by clause is required to get data in any particular
order.

but does it apply to select queries from ordered subselects also ?
eg

select   id , name , expensive_func(name)  from       ( select id , name from tab  order by c1 desc limit 15)  as foo
;

is it guaranteed that the final result is order by c1 ?

Regds
mallah.