Vulcan ranks

The military of the Vulcan High Command maintained a rank structure roughly equivalent to that of the Starfleet. 

Administrator
The Administrator of the High Command had the power to authorize military action against foreign governments. 
 * Administrator V'Las

Fleet Commander
A fleet commander reported directly to the High Command. They oversaw and commanded fleet engagements. 

Captain
Captain was the rank held by Vulcan starship commanders. 
 * Captain Oratt
 * Captain Sopek
 * Captain Tavek
 * Captain Tellus
 * Captain Tok
 * Captain Vanik
 * Captain Voris

Subcommander
Subcommander was a rank subordinate to a Vulcan captain. In dealing with Starfleet, a subcommander was considered above the rank of commander and below the rank of captain. 
 * Subcommander Muroc
 * Subcommander T'Pol

Major
Major was a rank held by senior Vulcan field agents. 
 * Major Talok

Subaltern
Subaltern was a rank that existed sometime before 2375. 
 * Subaltern Lorot

Sublieutenant
Sublieutenants were low-ranking members of the High Command, often manning security posts. 

Rank insignia

 * Sublieutenants do not appear to wear rank insignia.

Background information
The Vulcan rank system seems similar to the system used by the Romulans, perhaps suggestive of a common origin. Vulcans and Romulans are the only species in Trek shown to hold the ranks of subcommander and sublieutenant.

The ranks of commander and lieutenant have never been referenced onscreen, although their existence at some point in Vulcan history can be inferred by their subordinate ranks.

Vulkanierränge Rangos Vulcanos Vulcan rangen