Looking at the directory in which these notes appear,

http://pages.cs.wisc.edu/~madthanu/qual-notes/

these seem to be Thanumalayan Sankaranarayana Pillai's 2012 qualifier notes on Plan 9.

They're nice notes, but given the title (Notes on “Plan 9 from Bell Labs” by Rob Pike), readers interested in reading Rob Pike's notes on Plan 9 may be disappointed.

We added the year and shortened the title. Thanks.

This is not from 2012, this is ancient. It talks about IL and 8½, which were removed more than 13 years ago.

Ok, we'll take out the year until someone can suggest a plausible one. Though perhaps the author was working with obsolete info in 2012?

It's "Notes on (the paper) 'Plan 9 From Bell Labs, 1995', 2012"

The Barney Stinson homage, would put it at 2005 at the earliest (when the show started)

It's earlier than that, 4th edition was released in 2003, and IL and 8½ were removed between 3rd (2000) and 4th edition.