Ferengi ranks
Ferengi ranks was a hierarchical collective command structure, utilized by the Ferengi military, represented by various combinations of rank insignia, including pips and braids worn on the Ferengi uniform, and/or a small green tattoo worn on the right lobe. 

These were worn in any number of combinations, with the most common cases being DaiMons have a combination of all three of the highest defined insignia, and crewmen having all of the lowest, with all other officers peppered with combinations of various selections from all insignia types.

Types of insignia

Tattoos 
The tattoo was perhaps the most permanent adornment worn by Ferengi officers. It consisted of the Ferengi emblem, and depending on rank, additional chevrons next to the emblem. 

DaiMon's often wore a tattoo consisting of a logo and two chevrons. (, ) However, they were also worn by individuals who were not identified as DaiMon. () 

Lower ranked officers, such as a ship's first officer, doctor, or tactician, wore a tattoo consisting of a logo and a single chevron. (, ) While the lowest ranking crewmen, up to a ship's second officer, wore only a tattoo consisting of a the logo with no chevrons. These officers also typically wore none of the other insignia listed below. (, ) 

Finally, there were also instances of DaiMon's, and other officers, who had no tattoos at all. () With some even having had their tattoo removed. ()

{{bginfo|Debuting in the  episode "The Last Outpost" is what was considered "[t]he final makeup touch for each military Ferengi [..] a symbol, designed by Michael Okuda, that was hand-painted on the right side of the huge Ferengi cranial lobe and consisted of the symbol for the concept "dog eat dog" preceded by a rocker or chevron." According to Michael Westmore's ranking system, "[n]o chevrons means that the Ferengi belongs to the lowest ranks, one to two rockers means that he's an officer, and three rockers stands for a command rank, almost a general." (Star Trek: The Next Generation - The Continuing Mission (p. 62)) The symbols were painted "green for greed, envy, and the color of money." (Star Trek: Aliens and Artifacts (p. 74); )}} 

 Pips 

Many officer typically wore two sets of small golden or silver curved metal pips attached to the top of their collars, near the shoulders. 

DaiMon's often wore two pips arranged in a yin-yang pattern. (, , , ) However, they were also worn by individuals who were not identified as DaiMon. () And, likewise, there were DaiMon's who had no pips at all. ()

Lower ranked officers, such as a ship's first officer, doctor, or tactician only wore one half of these insignia on each part of the collar. () Most officers, however, wore no such insignia at all. () This may also include some DaiMons. ()

 Stripes 
Another indication of rank were thin silver stripes on the forearm of each sleeve. 

Higher-ranking officers, again typically DaiMons, wore two stripes on each sleeve (); however, there were those who wore two stripes that were not indicated to be DaiMons. ()

Lower ranked officers, again such as the ship's doctor or tactician, wore one stripe on each forearm, and typically always wore a single pip. ()

Ferengi of the lowest ranks wore no stripes; they typically did not wear pips and had only the tattoo consisting of a logo with no chevrons. ()

Background information 

Aside from the frequently referenced "DaiMon", no other rank titles were ever stated to correspond with the evidential attempt to indicate such a hierarchy. 

At one point during TNG Season 1, Mike Okuda drew up concept art, dated , that in accordance to their purported "mercantile preoccupation", gave the following tattoo-based rank designations:
 No chevrons indicated "crewmembers"
 One chevron indicated a "salesman, third class" (using Letek as an example)
 Two chevrons indicated a "salesman, second class" (using Taar as an example)
 Three chevrons indicated a "salesman, first class (assistant manager)"

The last version of the tattoo was never seen on the show, but was indicated to be reserved for "future big guys". (Star Trek: The Next Generation - The Continuing Mission'', p. 62)

Ferenginar