Stored Procedure Syntax - Variable Colon usage in Insert statements

UDA

Stored Procedure Syntax - Variable Colon usage in Insert statements

I apologize if this is a simple answer, but I was surprised today to find that the colon preceding a variable use in an INSERT statement was optional...

Consider this example:

CREATE TABLE Test_Variable_Syntax_Landing (
InsertType CHAR(10)
, caldt DATE
, weekofmonth BYTEINT);

REPLACE PROCEDURE Test_Variable_Syntax (asofdate DATE)
MAIN: BEGIN

DECLARE caldt DATE;
DECLARE wom INTEGER;

SELECT Calendar_Date, Week_of_Month FROM sys_calendar.calendar
WHERE calendar_date = :asofdate
INTO :caldt, :wom
;

INSERT INTO Test_Variable_Syntax_Landing
( InsertType
,caldt
,weekofmonth
)
SELECT
'With:'
,Calendar_date
,:wom --<--- With
FROM sys_calendar.calendar
WHERE calendar_date = :caldt
;

INSERT INTO Test_Variable_Syntax_Landing
( InsertType
,caldt
,weekofmonth
)
SELECT
'Without:'
,Calendar_date
,wom --<--- Without
FROM sys_calendar.calendar
WHERE calendar_date = :caldt
;

END MAIN;

CALL Test_Variable_Syntax (CURRENT_DATE);
CALL Test_Variable_Syntax (CURRENT_DATE-7);
CALL Test_Variable_Syntax (CURRENT_DATE-14);
CALL Test_Variable_Syntax (CURRENT_DATE-21);
CALL Test_Variable_Syntax (CURRENT_DATE-28);
SELECT * FROM Test_Variable_Syntax_Landing ORDER BY 2,1;

DROP TABLE Test_Variable_Syntax_Landing;

Both INSERT statements seem to work just fine (on my V12).

Is this accurate? Is there any practical difference?

I guess I've always used colons everywhere.

Thanks!
Stephen