The question refers to the number parameter in this msdn documentation
If you don't you can create multiple stored procedures in SQL-Server differentiated by number and drop them with a single drop.
create procedure dbo.stored_proc1 as select 1
create procedure dbo.stored_proc1;2 as select 2
-- returns 1
-- returns 2
-- drops both
I wonder if this feature is used by anybody for something useful or if it is just a historic curiosity.