STAR CHART: PLANETS -
PLANETARY CLASSIFICATION - G, H, I

Class-G example mentioned in the above STSC illustration: Delta Vega. STSC's classification of Delta Vega as Class-G is contrary to Encyclopaedia which classifies it as a Class-M planet. Delta Vega is located near the galaxy's edge, and is the location of an automated lithium-cracking station. Captain James Kirk attempts to maroon the mutated Gary Mitchell there in 2265 because, while habitable, the planet is visited only every 20 years by cargo freighters. Possibly Delta Vega retains Kaferian apples because several trees bearing this fruit, a favorite of Gary Mitchell, are created by him on Delta Vega using his ESP powers. [TOS: Where No Man Has Gone Before]

Class-H examples mentioned in the above STSC illustration:

• Rigel XII would seem to be a mistake by STSC. Its description in the STSC illustration does not match either the planetary classification letter nor the description of fierce storms as given in Encyclopaedia. The latter canon source states that Rigel XII is a barely habitable Class-M planet, racked by fierce storms, and the site of a small lithium mining operation headed by Ben Childress, visited by the USS Enterprise NCC-1701 in 2266 to obtain needed lithium crystals to restore the operation of the ship's engines. [TOS: Mudd's Women]
• Tau Cygna V is a Class-H planet, desertlike, and bathed in hazardous hyperonic radiation. The Treaty of Armens, established in 2255 between the Sheliak Corporate and the United Federation of Planets, cedes several Class-H planets, including Tau Cygna V, from the Federation to the Sheliak. A Federation colony is established on planet Tau Cygna V in the 2270s in violation of the Treaty of Armens. The Sheliak exercise their rights to order the colony removed in 2366. The treaty contains 500,000 words and took 372 Federation legal experts to draft. [TNG: The Ensigns Of Command].

Class-I examples mentioned in the above STSC illustration: Q'tahl is the Klingon planetary classification for the Federation Class-I designation. Such a planet is noted in [Enterprise: Sleeping Dogs]. The Klingon captain's log, in translation, is heard: "We destroyed their ship, but we've sustained damage in our port fusion injector. We've descended into the outer atmosphere of a Q'tahl-Class planet...." Q'tahl is the name of a planet in the Beta Quadrant, which presumably gives the name to a class of planet in the Klingon classification system. For the location of the planet Q'tahl, see Star Chart: Beta Quadrant - adjoining boundaries of the Klingon Empire, Romulan Star Empire, Gorn Hegemony and the United Federation of Planets.