Here is the page 11 entry I (and everybody else) had to sign at OCS regarding tattoos:
IAW MCO P1020.34G, I have been counseled this date concering the Marine Corps Policy on tatoos, brands, and body mutilation. I fully understand that any tatoos, brands, and body mutilation that have not been previously waived by MCRC or additional tattoos, brands, and body mutilation I may receive in the future might result in my disqualification and discharge from any officer program in the United States Marine Corps. Additionally, violation of the above mentioned order may disqualify me from being commissioned as a 2nd Lt.
The uniform regs say:
1004. PERSONAL APPEARANCE
"1. Marines will present the best possible image at all times and continue to
set the example in military presence. The Marine Corps uniform regulations
for standards of personal appearance and grooming are as specific as
practicable in order to establish the parameters with which Marines must
comply. Marines are prohibited from:
(a) mutilation of the body or any body parts in any manner, and;
(b) attaching, affixing or displaying objects, articles, jewelry or ornamentation to, through or under their skin, tongue or any other body part.
Female Marines, however, may wear earrings consistent with paragraph 3009.
(c) tattoos or brands on the neck and head. In other areas of the body,
tattoos or brands that are prejudicial to good order, discipline and morale
or are of a nature to bring discredit upon the Marine Corps are also
prohibited.
(d) this regulation does not prohibit necessary medical or surgical procedures conducted by licensed, qualified medical personnel."
I think "discredit" is very subjective and times/policies have changed because someone a little less liberal is interpreting the rules these days. Just a guess, though. I know when I mentioned tattoo my MOI flipped out and told me to at least wait until I got to TBS. Since then the urge has passed, though....