Q: What is the acceptable similarity percentage for a review paper?

For most journals, a similarity of 15% or lower is considered acceptable. At 17%, you are close enough, and shouldn’t really have any cause for worry. You could try to reduce it further, but if it’s too challenging at this stage, you can let it be. In the cover letter, you could mention that you’ve made your best efforts to keep the similarity percentage as low as possible. Note that journals do their own plagiarism check, but they don’t rely on this alone. Rather, they look at the manuscript in entirely and take a judicious call. So, again, you should be fine.

For more information, you may refer to these resources:

• Do I still need to reduce the similarity if it is 25% and most falls under method and legends?
• I'm concerned about the similarity percentage of my plagiarism check report. Please advice.

Now, as you are about to submit your manuscript, you may find it worthwhile to go through these resources:

• What makes a great submission package? [Video]
• The importance of manuscript submission readiness checks [With a downloadable checklist to get you started]

Hope that helps. All the best for your submission!