Why cant i use the field user in SQL Server 8? -

Maybe not really but the user has an error with the question below if I change it to userZ Works, why can not I use that name? Is a field unique instead of a keyword? (Or whatever is)

  To create the table, post 2 (id integer is not the primary key, the title is nvarchar (max), not body nvarchar (max), user integer references 1 ( Id) );    
 
 
 must be attached to reserved words, such as  user  brackets. 
 Take a look for a more thorough explanation. 
 
  create table 2 post NULL, [user] Post 1 (ID) of INTEGER references);