I am trying to pass a report parameter to a stored procedure (@Time) to dictate which Category values are returned in my data set via the WHERE clause and don't know the syntax to accomplish this correctly. I suspect a case/if will need to be used and I've done this before but not when needing to do a WHERE clause IN.

```
DECLARE @Time AS NVARCHAR
SET @Time = 'REG' --possible values of 'REG' and 'OT'

SELECT
f.[Category]    AS [Category]

FROM foo f

WHERE
@Time =  
  CASE @Time
    WHEN 'REG' THEN f.[Category] IN (A, B, C, D)
    WHEN 'OT' THEN f.[Category] IN (E, F, G) 
END

```