Use of FROM keyword on DELETE statement

The BOL and many other sources point out:


FROM

Is an optional keyword that can be used between the DELETE keyword and the target
table_or_view_name, or rowset_function_limited.

I'm used to write DELETE sentences without the FROM. I've made some searches but can't find where the FROM is mandatory. Can anyone point out a situation where it should be mandatory? Or is always optional?

Here is one case where it would be hard to write it without:

DELETE /* FROM */ t1    -- this FROM is optional
  FROM dbo.t1           -- this FROM is mandatory
  INNER JOIN dbo.t2 AS t2
  ON t1.key = t2.key
  WHERE t2.key IN (1,2,3);

Or:

DELETE /* FROM */ t1    -- this FROM is optional
  FROM dbo.t1           -- this FROM is mandatory
  WHERE EXISTS
  (
    SELECT 1 FROM dbo.t2
    WHERE key IN (1,2,3)
    AND key = t1.key
  );

The FROM in the initial spot (e.g. DELETE FROM t1 FROM dbo.t1 ...) is optional, just as Books Online says. Why do you think it ever should be mandatory? Borrowing from Thomas' answer, which he gracefully deleted, the following are identical:

DELETE Sales.SalesOrderDetail WHERE SalesOrderID = -1;

DELETE FROM Sales.SalesOrderDetail WHERE SalesOrderID = -1;

This is similar to INSERT - the following are absolutely 100% equivalent, and you don't ever have to write INTO:

INSERT dbo.t1(key) VALUES(1),(2),(3);

INSERT INTO dbo.t1(key) VALUES(1),(2),(3);

StackExchange Database Administrators Q#57282, answer score: 14