Treatment: A variation from the normal 6 attributed releases. They include translucent plastic, unique color combinations, among other gimmicks.
For New Vestroia specifically, there is some confusion as to the treatment naming conventions. The individual waves are named after treatments. BakuNeon, for example, is the first wave. It introduces Neon treatment. BakuSteel is the fourth wave, which introduced Steel treatment.
The final New Vestroia wave is called B3, which abandons the previously established B1 and B2 size-based naming convention. B3 Bakugan are the same 32mm size as B2s.
During the B3 wave, most Bakugan were re-released with a focus on treatments- which had been renamed after their initial waves. Neon and Steel Bakugan released during the B3 wave are called BakuNeon and BakuSteel on the packaging, but not if they were released prior to this wave...confusing right? The treatment itself is unaltered and fundamentally the same despite this.
The documentation will use "Neon" and "BakuNeon" interchangeably and likewise for every other treatment, because it is a matter of useless semantics at this point. You are looking for a neon or steel colored toy regardless of what wave it actually came out in.
Likewise, if the toy in question had a chance of releasing in either wave, due to the near impossibility of tracking down this information, both waves are listed in the "First Released" category. See the Waves information further below for more info.

Bakugan releases differ by regions of the world. Below are the identified major regions, though specific countries would obtain specific releases on occasion. The identified regions are as follows:

- Japan (Sega Toys releases)
- South Korea (Sonokong B1s, otherwise part of Asia Region)
- Anglo-America (Canada has slightly different releases)
- Western Europe/Latin America (Nations south of the USA received European waves)
- Eastern Europe/Middle East (Primarily Russia and Post-Soviet nations)
- Asia + Australia (Appears to have received a mix of everything else. Documentation is poor)

Note:
Rarity scores are based on how easy the Bakugan is to find for a primarily American buyer, however Sega Toys and Takara Tomy releases have scores based on their own region. This means that if you live outside of the designated region, increase the rarity score by one or two points.

For example, Hydranoid is 6/10 (Moderate) in the US, and did not release in Japan. If you live in Japan, it is likely 8/10 rarity instead.
If a European Bakugan is considered Common (say 3/10), then to an American, consider it Moderate (say 5/10).
This is is because you would have to go out of your way to find sellers or utilize websites or middlemen, and are also likely to have to pay an increased cost in order to obtain it along with international shipping. This effectively raises your barrier to entry, even if the toy in a vacuum is not difficult to find.

- 1/10 - 2/10 (Very Common): Easy to find and relatively cheap, you will likely find a minimum of 10 results upon searching for one online
- 3/10 - 4/10 (Common): Relatively easy to obtain, slightly less numerous and more expensive. Will find a few results in a search
- 5/10 - 6/10 (Moderate): Potentially annoying/expensive to track down, but realistic enough to obtain without too much issue
- 7/10 - 8/10 (Semi-Rare or Rare): One will pop up every few weeks or months. You may have some competition in trying to obtain this
- 9/10 or 10/10 (Very Rare): Realistically, you will not obtain this Bakugan. Get a custom paint job or a recast. Good luck otherwise
- One-Offs: An anomaly that probably shouldn't exist, but has been documented for the sake of completion