911T options

[AbbyAk]

I have a 1971 911T that I inquired to classic Porsche about it's delivery destination and option sheet etc. The reply I got was this:

Concerning your request for information about your Porsche 911T we could find out the following delivery details:

(gives serial number, delivery city (L.A. Culver City), engine/gearbox info, color (silver metallic), interior (leatherette) etc )

Then the Options:
Light alloy 6J x 15 and tires 185/70 VR 15, stabilizers front and back, 911S instruments and OILTANK (?), leather steering wheel , tinted glazing, electric sunroof.

My question is this: What is a 911S oiltank? Does this mean a different fuel tank. Sorry if this is a newbie question. Any info appreciated.

A.B.