offerID is the thread # which represents the thread posted. I see in forums posts are represented by random numbers. Is this achieved by IDENTITY? If not, please advice.

nvarchar(max) will carry all kind of texts along with HTML tags.

CREATE TABLE Offer
(
    offerID           int IDENTITY (4382,15) PRIMARY KEY,
    memberID          int NOT NULL REFERENCES Member(memberID),
    title             nvarchar(200) NOT NULL,
    thread            nvarchar(max) NOT NULL,
        .
        .
        .
);