How to reference a technical document (like an RFC) in APA style? Like, this document, for instance: 
https://tools.ietf.org/html/rfc791

It's an official Internet Engineering Taskforce document that defines things like network protocols, etc. Often times there's really no specific individual(s) credited as the author(s), and even the official title can seem ambiguous.

The information on the title page is:



INTERNET PROTOCOL
DARPA INTERNET PROGRAM
PROTOCOL SPECIFICATION
September 1981

prepared for
Defense Advanced Research Projects Agency
Information Processing Techniques
Office
1400 Wilson Boulevard
Arlington, Virginia 22209 

by
Information Sciences Institute
University of Southern California
4676 Admiralty Way
Marina del Rey, California 90291



So what's the official title and who get's the credit; DARPA, IPTO, ISI, USC, or IETF? I was going to do something like below, but I thought I should check with you guys.



DARPA. (1981, September). Internet Protocol Specification. RFC 791. Retrieved from https://tools.ietf.org/html/rfc791
The APA Style blog walks you through citations with missing info. There is also how to cite a book with no author or editor. You seem to be using DARPA as the author, but from the title page, it seems mote likely that ISI/USC is the institutional author. If you dig deeper, the linked document lists Postel as the editor. In that case you just do a book without an author, but with an editor: https://owl.purdue.edu/owl/research_and_citation/apa_style/apa_formatting_and_style_guide/reference_list_books.html

Edited Book, No Author
Duncan, G. J., &amp; Brooks-Gunn, J. (Eds.). (1997). Consequences of growing up poor. New York, NY: Russell Sage Foundation.