CREATE TABLE dbo.GenderTitle (

Title varchar(50) PRIMARY KEY,

Gender varchar(20) not null

)

INSERT INTO dbo.GenderTitle

(Title, Gender)

SELECT 'Mr', 'Male'

UNION

SELECT 'Ms.', 'Female'

UNION

SELECT 'Mrs.', 'Female'

SELECT *, ISNULL(Gender, 'Unknown') Gender

FROM dbo.Person P

LEFT JOIN dbo.GenderTitle GT ON GT.Title = P.Title

Hope it helps.