Example CREATE TABLE and CREATE INDEX

/******************************************************************************************
    RGExampleTable

    This table stores sample information.
 ******************************************************************************************/
PRINT N'RGExampleTable'
GO
IF NOT EXISTS (SELECT 1 FROM sys.objects WHERE name = N'RGExampleTable' AND type = 'U') BEGIN
    CREATE TABLE RGExampleTable (
        EntryID         int             NOT NULL    IDENTITY,
        AccountID       int             NOT NULL,
        Active          bit             NOT NULL    CONSTRAINT RGExampleTable_Active_DF          DEFAULT 1, -- Active when inserted
       
Description     varchar(255)    NULL,
        ChangedByUserID int             NULL,
        DateLastUpdated datetime        NOT NULL    CONSTRAINT RGExampleTable_DateLastUpdated_DF DEFAULT GETDATE(),
 
        CONSTRAINT RGExampleTable_PK PRIMARY KEY CLUSTERED (EntryID),
        CONSTRAINT RGExampleTable_AccountID_FK FOREIGN KEY (AccountID) REFERENCES dbo.RGAccount (AccountID),
        CONSTRAINT RGExampleTable_ChangedByUserID_FK FOREIGN KEY (ChangedByUserID) REFERENCES dbo.RGUser (ChangedByUserID)
    ) ON ExampleDB_FG2
END
GO

IF NOT EXISTS (SELECT 1 FROM sys.indexes WHERE name = N'RGExampleTable_AccountID_IDX') BEGIN
    CREATE INDEX RGExampleTable_AccountID_IDX ON dbo.RGExampleTable (
        AccountID
    ) ON ExampleDB_FG3
END
GO

Instead of binding rules to columns, use either reference tables or check constraints.