Exempt means, the security is exempt from registration with the state because of a myriad of reasons. If the issuer is exempt that means he is exempt from registration with the state.

IT people come under 'Exempt' Category.

No, "exempted" is the past participle form of "exempt." The past tense of "exempt" is "exempted" as well.

Exempt interest and exempt dividends from qualified municipal bonds.

Exempt employees are 'exempt' from federal overtime rules and regulations, based on specific qualifications put forth by FLSA rules. (Executives, professionals, etc.) Non-Exempt employees are paid by the hour, and are subject to federal overtime rules (time and a half, for all hours worked over 40 in a pay week.) All hourly employees are non-exempt, all exempt employees are salaried, but not all salaried employees are exempt. Salaried employees must pass specific FLSA criteria to be categorized as 'Exempt', and therefore exempt from overtime rules.