During Recruit Training

;g;ihb;ighoemkabr[o'ej/adsnfg[0yfAEMarines address all enlisted personnel by rank, and all Commissioned officers with "sir" or "ma'am". Warrant Officers, regardless of rank, are addressed just as commissioned officers, but may also be addressed as "Warrant Officer", or "Gunner", although the latter is sometimes considered improper unless the officer is an Infantry Weapons Officer (MOS 0306). During recruit training, recruits are indoctrinated to address all superiors as "sir" or "ma'am".

The most junior ranks between pay grades E-1 and E-3 (Privates, Privates First Class, and Lance Corporals) are also referred to by proper rank and/or last name only, though the latter is informal.

During recruit training, recruits are not considered full-fledged Marines and must address all Marines who have completed recruit training, including instructors, as "sir" or "ma'am." Incoming recruits must also refer to themselves in the third person (i.e. "this recruit"), and their rank is replaced with the word "Recruit." This usually continues until the last week of recruit training when, in most instances, recruits are then considered full-fledged Marines. Likewise, during officer training, officer candidates are not yet commissioned Marine officers and must refer to themselves as "this candidate" or "the candidate," even though some officer candidates may hold an enlisted rank. During Officer Candidate School, each candidate is referred to as "candidate" and not "Marine." Unlike their enlisted counterparts, officer candidates refer to enlisted Marines, including their instructors, by their full and proper rank; only commissioned officers are addressed as "sir" or "ma'am."

Informally, some enlisted ranks have commonly used nicknames, though they are not official and may be improper for use in formal situations. The acceptability of nickname use by juniors is at the discretion of the individual rank holder. A Gunnery Sergeant is typically called "Gunny" and occasionally "Guns", a Master Sergeant is commonly called "Top" (which was an extremely racial term in the late 60's because the white officers and enlisted did not want to refer to blacks and hispanics as "Master", so they coined the term, "Top"), a First Sergeant is sometimes referred to as "The First Shirt", and a Master Gunnery Sergeant is "Master Gunny" or "Master Guns". Differing from the Army and Air Force, all ranks containing "Sergeant" are always addressed by their full rank and never shortened to simply "Sergeant" or "Sarge". A Private First Class is usually referred to as a PFC, instead of simply "private"; similarly, Lance Corporal is not shortened