These keywords need Merging

First two are practically identical contextually, but I'm not that sure about the third one: some of the cases of the latter are so brief, that they're not in the usual R/16+ category. For example I was not even able to remember where said brief nudity is in PG-13 movie The Big Picture (1989) which happens to be first in this keyword and I saw it fairly recently and it turned out to be rather memorable movie in my book. Movie's parents guide reminded me that there is, indeed, a scene with brief nudity, but it's barely in focus and is never prminent in the movie. I therefore can say that the third keyword actually has certain merit on its own. 

The second keyword in your list ("full-frontal-female-nudity") has been merged into the first ("female-full-frontal-nudity").

Regarding the various "brief" nudity keywords, I just posted a new list, linked below, in which I propose merging several of these keywords. 

Here is the basic idea: retain the "brief" part of the keywords, while merging them all into "brief-female-nudity" or "brief-male-nudity." This will reduce the variations of these keywords and thereby make them more manageable.

brief-female-full-frontal-nudity (93 titles)  -->  brief-full-frontal-female-nudity (13 titles)  -->  brief-female-frontal-nudity (120 titles)  -->  brief-female-full-rear-nudity (14 titles)  -->  brief-female-rear-nudity (79 titles)  -->  brief-topless-female-nudity (176 titles)  -->  brief-female-nudity (243 titles)

brief-male-full-frontal-nudity (80 titles)  -->  brief-male-frontal-nudity (251 titles)  -->  brief-male-full-rear-nudity (14 titles)  -->  brief-rear-male-nudity (11 titles)  -->  brief-male-nudity (21 titles)

Duplicate Keywords - List #57 (Proposals for Permanent Merger and Auto-Conversion) (nudity keywords pt. 3)