C: Enjoyed it and would recommend it with perhaps a few reservations or caveats.
D: An okay read and would recommend it with several reservations or caveats.
F: Didn’t work for me for whatever reason.
I buy some, but not all, of the books I review on my blog. I get several books for free at various book conferences I attend every year or check them out for free from my local library. Occasionally, I am asked to read and give cover blurbs for other authors’ books. I also occasionally review books for a magazine.