Can somebody explain this strange sql statement

It's a webbsite using C# and ado.net to access a oracle database. Below is just the beginning of the sql select statement that is used and here you
can see form_slag and I wonder
how this is possible. This form_slag looks like a variable. If I look at this sql select statement just before dataadapter.fill is executed I see this form_slag just as it is in the select statement below. What seems very strange to me is where is the actual value for this form_slag is given.
This form_slag must have a value before the dataadapter.fill is executed but it has not or it must be fetched from the database in some way that I don't understand.

Note as I wrote earlier this is just the beginning of a large sql statement.

I have two questions.
1.Can anybody explain how this form_slag can be used in the way that it is used ?

2. What does it mean when we have this in the select statement '2'; as send_ro_roles ?

select distinct form_nr,
'2;' as send_ro_roles,
'2;' || k.kli_klia as roles_and persons,
k.klia_namn as klient_ansvarig,
(
select distinct bizref_check_freq
from bizrulereference
where bizref_date =
(

   select MAX(bizref_date)
   from bizrulereference
   where BIZREF_FORM_TYPE = form_slag

//Tony Received on Mon Jul 18 2011 - 03:56:22 CDT