659 - INSTRUCTOR (Designated Specialty)  
[INSTR (***)]

Gives instruction at a service school, training center, or field unit in one or more subjects for which there is no combat or operational MOS counterpart, and for which there is no specific instructional MOS listed elsewhere in this manual.

695 - ORDERLY

Attends and accompanies a commanding or an executive officer and performs such routine duties as delivering and receiving messages, announcing visitors, and running errands.

837 - COMBAT CONDITIONER  
[CBT CONDITIONER]

Instructs troops in one or more of the following combat techniques:

870 - CHEMICAL WARFARE SPECIALIST
[CW SPL]

Trains others in defense against gas attack by familiarizing men with methods of detecting and identifying gases, with use and care of gas masks and protective clothing, with decontamination techniques, and with first aid treatment to gas casualties.

998 - Special Assignment  

An enlisted Marine regularly performing duties of a highly specialized nature that are not covered by one of the military specialties described in this manual.