- Please keep these annotations SPOILER-FREE by not revealing information from later pages in the novel.
Page numbers refer to editions with 369 pages, where the story begins on page 1. Not sure if there are other editions with variant pagination. Please let us know otherwise.
Brylcreem is a hair styling oil/gel for men that was very popular. It gives hair a wet, oily look.
on the natch
"natch" is short for "natural" and "on the natch," in this context, means sober. On pg. 273, the perennially sober Bigfoot is described as a "literal-minded natch-meister."
A real high school, in Lawndale, California, which - particularly in the story's time period - was a relatively undesirable and low-priced city in the LA area.
Probably a play on the term of Russian origin, meaning a man with underworld connections or a career criminal.
Section Eight hippies
Section Eight is low income housing funded with a federal subsidy.
"Japonica" is just a Latinization of "Japanese," but it is most commonly used in formal Latin plant names. There are a wide variety of "____ Japonica" plants, such as the Camellia Japonica. While it's not really possible to make any universal statement about such widely varied species, they tend to be ornamental and hardy. See: Plants of Inherent Vice
It is possible the first name is inspired by the character "Crocker Jarmon" from the movie The Candidate (1972). The character in the movie is an establishment, incumbent GOP Senator from California.
the ancient American Indian belief that if you save somebody's life, you are responsible for them from then on, forever
Last seen in Against the Day with Foley Walker and Scarsdale Vibe.
Ronald Reagan was governor of California from 1967 to 1975.
ten-year-old Mercedes sedan with a roof panel
late rush-hour traffic
Should be afternoon, the thirteenth day of the narrative, Sunday, April 5, 1970, but why would there be rush hour traffic? Why would postcards be delivered today, and why would the Golden Fang be open?.
outdoor concerts where thousands . . . public self
A good description of Woodstock, which had just taken place the previous year.
each person was listening in solitude, confinement and mutual silence
Perhaps a foreshadowing of the iPod generation?
Here, "head" refers to drugs, as in "head shop".
Doc noticed (a) it was now dark
Should be evening, the thirteenth day of the narrative, Sunday, April 5, 1970.
Things were weird for a few days with the Dart
The timeline gets broken here. From the end of the book to this point--from April 26 to May 8--the narrator has made it easy to follow the events of the book in real time. The narrator puts Doc to bed at night, gets him up in the morning, points out television shows and events.
The first half of the book, thirteen days up to the "few days" the Dart was in the shop, can also be matched with real time events. For example, Doc's parents visit during a division semifinal game between the 76ers and the Bucks. That series was played from March 25 to April 3. That would mean that the Dart was in the shop for a couple of weeks. Given the regret that Doc felt over a less-than-24-hour delay in the first and second days of the narrative, it's difficult to believe that he would drop the case for that long. Perhaps some kind of Dark Shadows parallel time is at work.
Or maybe Pynchon, contrary to reputation but like most authors, hasn't been perfectly careful about the relationship between his story's timeline and the real calendar's.
When he finally went over to pick up his ride
Probably morning, Saturday, April 25, 1970. See below for an explanation of "probably". The obvious reference is to the resurrection of Jesus Christ, who also came back on a Sunday. This is not Easter Sunday, though. It occurred on March 29 in 1970.
Prefabricated metal building with a semicircular cross section. 
'64 Dodge Dart
I'll buy you lunch
Probably morning, Saturday, April 25, 1970. I say probably because it seems unlikely that Doc could have lunch with Tito, make a few phone calls, and drive to Ojai, getting there before lunchtime. The narrator has been pretty careful, though, from the end of the book to this point in noting the ends and beginnings of days.
They went down Pico . . . before repeating an ethnic category.
A possible nod to noted LA chowhound Johnathan Gold, who got his start as a Pulitzer Prize winning food critic eating his way across ethnic LA along Pico Blvd. Profiled here on NPR's "This American Life" (See: Act Five. Taste.)
1934 Hispano-Suiza J12