Mata Nui's Guide to Bara Magna
- bone hunter*
- dune snakes
- dune wolves
- fire tribe
- ice tribe
- iron wolves
- jungle tribe
- rock steed
- rock tribe
- sand bat
- sand stalker
- sand tribe
- water tribe*
Makuta's Guide to the Universe
- adaptive armor
- ash bear
- avohkah* (shows up uppercase once and lowercase once in Makuta's Guide to the Universe, but lowercase in Takanuva's Blog; based on that I think it's lowercase)
- the cord
- Cordak blaster (lowercase b)
- doom viper* (uppercase in Rahi Beasts, maybe the Legends books; lowercase in Reign of Shadows)
- keras crab
- kini (on its own)
- kolhii (we can infer koli too)
- krana (except when a suffix is applied - e.g. "Krana Za")
- Makoki stone (lowercase s)
- Mangai volcano (lowercase v)
- metru (on its own)
- Midak skyblaster* (lowercase s) (bionicle.com has it as uppercase)
- Motara desert (lowercase d; interestingly, listed in the index as just "Motara," but places like "Fau Swamp" have the whole name listed...)
- Nui stone* (uppercase s in The Many Deaths of Toa Tuyet)
- Nynrah ghost blaster (Lowercase g and s. This is an interesting case since I think the Nynrah Ghosts were canonized after the blaster. This led to weird situations, like in Federation of Fear when they're called just a "ghost blaster." Maybe people in the MU didn't know they were named after the Nynrah Ghosts. I bet if we asked Greg about this now, he'd say it's properly "Nynrah Ghost blaster" with a capital g.)
- Rhotuka launcher, Rhotuka spinner (lowercase l, s)
- rock worm
- shadow leech
- time slip
- Toa seal (lowercase s)
- Toa stone (lowercase s)
- treespeak (we can infer chutespeak too)
- Tridax pod (lowercase p)
- Visorak venom (second v is lowercase)
- wahi (on its own)
- zamor sphere, zamor sphere launcher
Words you might expect to be improper nouns, but aren't:
- Charred Jungle (though once referenced as "Charred Forest" in the BEU lavaboards entry)
- Cliff Village
- Fau Swamp
- Gukko bird
- Hahnah crab
- Knowledge Towers
- Manas crab
- Nektann (referring to the robots)
- Nui-Rama (spelled Nui Rama in the book)
- Nui-Kopen wasp
- Takea shark
- The Shadowed One (uppercase T)
- Ussal crab
* Names that have shown up as proper nouns in other canon media at some point. Not an exhaustive list.
I've found that the written serials are surprisingly consistent with the capitalization outlined above, but they seem inconsistent because the transcribed podcasts keep everything capitalized. For example, "kolhii" is lowercase in Reign of Shadows, a written serial, but it's uppercase in Dark Mirror. That's not because Greg was inconsistent, it's because Dark Mirror was transcribed by us. It's similar for other words too, like "kraata." The only instance of an Agori "tribe" being capitalized the Legend Reborn guide which alludes to the "Water tribe."
Since WoH doesn't have text from guides, my ability to scour them is limited to where I or others in the TGA server remember to look, but here's what we've found so far. In some cases, the wiki has been updated to reflect these findings; however, somehow or another, this information should be present and easy to find.
Words with no known uppercase instance (though the possibility exists that an exception may be found, transferring it to the other list below)
- "Matoran universe" and not "Matoran Universe" (the only exception to this was in Into the Darkness which, being an audio transcript, has since been fixed.)
- "Makuta stone" and not "Makuta Stone"
- "Mata Nui stone" and not "Mata Nui Stone"
- "Destiny war" instead of "Destiny War"
- "southern islands" (or "southern lands" or "southern regions") instead of "Southern Islands"
- "red star" instead of "Red Star." Of Greg's works (including his responses to fans) this one is only ever capitalized in Riddle of the Great Beings (which was an audio transcript). The only uppercase instances occur in Nixie's dialogue in MNOG, but it's ambiguous if this qualifies as canonical.
- Toa code? Haven't fully looked into this one.
Words with only one known uppercase instance
- "northern continent"/"southern continent" only appear in the lowercase in-story or even guides... except for one uppercase instance on the map in MGttU (even though there is also a fully lowercase instance on the same page).
- the phrase "Toa stone" appears almost thirty times in-text, always ever as "Toa stone." The only exception to this is also found in Makuta Guide to the Universe.