The Trevor Phillips Enterprises (T.P.E.) Blueprint Map was included in the Special and Collector's Editions of Grand Theft Auto V.

T.P.E TREVOR PHILIPS ENTERPRISES
WEAPONRY + NARCOTICS + INTIMIDATION + CASUAL WEAR

X
Lago Zancudo
Great Ocean Highway North
through north Chumash
0.5 miles past Raton Canyon
← when guard rail ends
follow the dirt road
down the Docks
Bring $500,000 CASH
XXXXX

Visiting the Location indicated by the secret message takes the player to a remote dock available for purchase. A Mini submarine is stored there, and offshore a number of Nuclear Waste barrels may be gathered for cash.

Inverted version of the Blueprint map with all hidden markings.

The map shows locations for fast cash, safehouses, custom rides, armoured cars and Nuclear waste barrels in the ocean requring a submersible to retrieve. The map is also filled with a bevy of hidden messages and symbols only visible on the Original Blueprint Map with a UV light.

Deciphering the Text and Symbols

Safe House

GTA Online Properties available for purchase. You can only own one at a time.

Fast Cash

Liquor stores, Gas Stations and Convenience stores to hold up.

Custom rides

Pay and Spray, Los Santos Customs.

X Submersible

Appears to denote general locations to search for Nuclear Waste. Although there are only 10 X's there are 30 Nuclear Waste barrels.

Ø Gruppe 6

Approaching these sites triggers a random event where you can steal money from an armoured car.

Simeon Vehicles for fast cash

GTA online. Simeon will text you a list of cars he needs, you can only bring him one on the list. Damaging the car will decrease the amount of money you will receive. Occasionally he will have a priority vehicle for you to retrieve that will be marked on your map.

Flying Saucer

Visiting the Locations indicated by the Flying Saucer reveals an extremely well concealed Spaceship Part.

Titan / P.996 Lazer / Buzzard

Fort Zancudo, An army base where you can acquire Military aircraft such as the Titan (Cargo Plane), P.996 Lazer (Fighter Jet) and Buzzard (attack chopper).

They're Here!

Two odd cylindrical buildings covered in alien drawings and symbols with a couple of people doing yoga on the roof. Also a Spaceship Part up the mountain on a ledge. 

9A

Extremely difficult to search the BolingBroke Penitentiary, Even with the Lower wanted level cheat. Only item found was a Machine Gun on a raised walkway connecting the 9A building to a watch tower.  It's possible the 9A block is where Trevor believed Brad Snider was being held. The angled wall in the yard in front of building 9a has a message about the random #8s in the game as well as a pic of a island chain similar to the one at the top of the map or get gta 5 online money. 

In the Drink

Recommended to approach by Sea, It will reveal an alcove in the hills with a Letter Scrap on a small beach and a Spaceship Part and Grenade Launcher in the Water.

Rail cabin

The only item found at this location was a Sawed Off Shotgun.

sw rooftop

National Office of Security Enforcement, smash the gates and climb onto the rooftop to find an RPG and Buzzard (Attack Chopper).

Shoot for the stars

Galileo Obsevatory, Sniper Rifle by a telescope and Body Armor by the electrical transformers.

under the rock face

Body Armor on the higher part of the road and a Letter scrap on the lower.

stash

A small outdoor weed farm guarded by a few gang members. A suitcase with cash can be found inside the shed, which respawns every week.

open grave

A fresh dug plot with a Pistol inside.

pink pool

Body Armor on the pool deck.

backyard davis & grove st

Various Items can be found in the backyards of Davis & Grove St. Health, Body Armor, SMG and a Letter Scrap.

frank mathers

After purchasing the Sonar Collections Dock In Paleto Cove. A Strangers and Freaks mission will become available to Michael. The wife of the deceased Frank Mathers will task you with finding his destroyed Submarine Parts.

between the crates

A strange cult community where everyone runs around in their underwear. Be prepared for a fight once inside the compound, Go to the farthest house on the right, on the porch there are an Assault Shotgun, RPG and Armor. Baseball bat is nearby on a rock.

You can also bring an unsuspecting victim to the cult for a cash reward.

CBL-Omega-Flying saucer

Carbon Based Lifeform. The symbol next to "CBL" is the symbol for Omega. This most likely alludes to the location to start the "Strangers and Freaks" mission where you help Omega find the spaceship parts.

Bridge with Arrow

On top of the bridge you will find an RPG.

explosion in Alamo Sea

Simply a Grenade at the end of the Dock.