In APPENDIX C of the TOS Section 2
xi. Community Members may not broadcast, upload, or offer any content referencing or depicting "bukkake" or "goatse".
Okay I get why CB might wish to make "goatse" verboten. However "Bukkake" is basically Japanese term for a facial involving multiple cum providers[1]. There is some backstory about how the practice came about as a way to punish disobedient women but frankly that sounds like something made up by teenage boys. The real origin is most likely that some people find cumming on women to be fun.
Since facials are not banned on CB it seems strange that using this exact term is banned.
[1] Okay it literally means noodles but I think you can work out how the etymology came about.