The increase of coupon rate is actually the increase of coupon rate. At first, it may be 5% in coupon rate, but later it is raised to 10%, so the issuer will have to bear more interest.

Coupon rate is coupon rate, which is the interest paid to you at par value every year or every six months as agreed at the time of issuance.

Bond enhancement means enhancing income, that is, the fund manager invests most of the fund's assets in the bond market, and then invests a small part of the funds in the stock market, so that there are both fixed interest rates on the bond face and excess income brought about by stock market fluctuations.