Stabshauptmann (Bavarian Army experts needed)

[Deutschritter]

Gentlemen, I am not sure, if this is the correct category, but I need help with a rank: The Stabshauptmann, as we understand it today, even with the Bundeswehr, was/is a rank between Oberleutnant and Hauptmann (I. Klasse), often historically classified as Hauptmann II. Klasse. In Bavaria around 1866-68, officers like Benignus von Safferling (8. Jäger-Bataillon) and others, already Hauptmann I Klasse, would be promoted (appointed?) to/as Stabshauptmann, although the Ranglisten still showed them as Hauptmann I Klasse. Therefore my question: Was the Stabshauptmann not a rank at all but instead a Dienstbezeichnung (job title)? Maybe the senior Hauptmann I Klasse, not leadig a company, but placed into a battalion staff as deputy of a major? Thanks for any information! 

Edited February 12 by Deutschritter