Which credit section?

It would be great if I could get a clarification on the following. On many occasions, I notice a credit that would normally go into the Additional Crew section unless if the job is followed by the company that the artist is working for. For example, 'finance director' normally would go to the Additional Crew section, but I find 'finance director: Cinesite' in the Visual Effects section because Cinesite is a visual effects company. I see this same thing frequently for other jobs and other companies. So, I guess in a broad sense, the question is, "What determines the credit section the job goes into - the job itself, or the company that attaches to it?"

Here's a slightly different example. In THE MARVELS there is a section of credits under the heading 'Visual Effects and Animation by Sony Pictures Imageworks'. One of the credits is for a Davin Hun, credited as 'production coordinator'. However, IMDb has him credited as 'visual effects coordinator' in the Visual Effects section. Why wouldn't his credit be 'production coordinator: Sony Pictures Imageworks' and placed in the Additional Crew section?

I can see the fact that these artists are working for specialty companies can imply the job has something to do with that specialty, but does that trump the actual name of the job, placing it in the specialty section rather than the Additional Crew section? If so, it would help if that were clarified in the Rules.

Thanks for reading.