I'd be delighted to, there's no set in stone list of ranks, but there are ones that are widely know, I'll list the ones i believe work best and were how I did it with my guild back in the day. I'f you desire to do it for another game there is a longer list which i shall post too.
There are three tiers I stage this in you may ignore the first two if you wish as they are for larger populated groups (I kinda stage my guild more like an empire XD)
Chief of all the tiers is the Pirate Council (The Brain):
Pirate King - Head of the armada, oversee's the council and larger scale fleet battles who manages the executives
Then there are 6 pirate lord
Treasurer - Takes inventory on fleet and overall armada wealth, assisted by logistics officers
Secretary - Develops the agenda for the armada, assisted by one to two fleet officers
Admiral - coordinates fleet advances and activities.
Guerrilla - coordinates land advances and activities.
Diplomat - coordinates affairs with other guilds/armadas
Handler - Supervisor of the trainers and master of innovative strategies.
The Council is the spider of the web, These six positions of authority will govern 20 to 200 pirates.
Tier II (The Nerves):
Rooke - Basically the head of the second tier, all officers report to this position, who then reports to a Pirate Lord or the King
Fleet Officer - Each is in charge of it's own fleet and is responsible for any active duty fleet actions
LL (Land Lubber): leaders of land engagement
Officer - general command of the armada, usually assists a fleet officer or the Handler as officers are only promoted with experience
The second tier is how the Council executes commands or decisions. without it, the Council would have to do a lot on their own.
Ok here's what you were looking four, Tier I, the body, the crew:
Ship's captain - I mean, it's the captain, pretty straight forward, keeps the crew from falling apart.
Quarter Master - Represent's the crew and the captain, it's the VP but also the chief justice for minor offenses
Boatswain - Supervises maintenance and cargo on the ship, he's the guy that keeps yelling at you to work harder ( alternatively called Bossun)
Master gunner - responsible for ships guns and ammuniton n/a to POTCO though
------------------ The rest really isnt rank its just general crew but each has its importance
Carpenters - Fix the ship
Mate - apprentices to Quarter Master and Captain and such (First mate is usually the Captain's apprentice
A.B.S. (Able-Bodied Sailor): Common Sailor
Rigger - these guys are the ones you see dangling from the masts furling the sails.
Cabin Boy - Kid's who do misc. chores on the ship, mostly washing dishes and peeling potatoes like you would be working kitchen police in the marines.
Powder monkey - gunners
Swab or "Swabbie" : Technically not a rank but there the ones who swab the ship, its become slang for the newbies or someone who you don't hold in high regard.
Sorry I gave you more than you asked for but I figured it might help some of the people out there who want to make a bit bigger guilds when this game gets back up and running. If you or anyone else has any questions about building an empire, be it pirate or any other kind I'm your man! Hope this helps!