Question 911 Porsche Workshop Manual

[AKIRA KASAI]

Porsche workshop manual has the following sentences.
see page SF35, shown on page SF36.
Please tell me the meaning of “SF”.
And please tell me how to get the manual indicated by “SF”.

[Thomas Frisardi]

Porsche workshop manual has the following sentences.
see page SF35, shown on page SF36.
Please tell me the meaning of “SF”.
And please tell me how to get the manual indicated by “SF”.

"Fuel [system] supplement"

[AKIRA KASAI]

On 911 Porsche Workshop Manual, sometimes I found description of "shown on page SF", "see page SF" and page number.
I cannot understand "SF" meaning.
Is it something manual book name?
Please tell me the meaning of "SF", and how can I get this one.

[Jon Bunin]

Please tell me the meaning of "SF", and how can I get this one.

"SF" pages were supplements to the original "F" (Fuel) pages of the manual.
The original 911 manual pages covered Solex carburetors, while supplemental pages covered Weber, MFI and Zenith fuel systems.
Manuals printed in later years had these supplements included. It will be difficult to find original supplements to update an early manual, except for scans or photocopies.

[AKIRA KASAI]

Thank you for your answer.
I will try to retrieve it on the Internet.