So what does all that junk mean, to the uninitiated in the vagarities of Digimon classification (and even those that are are probably scratching their heads over the listing of "Codex B-73")?
Picture
Well, this is pretty easy--a picture of the Digimon. Most of the pictures are official Toei or Bandai portraits, and were probably mined from The DigiPort, Shining Evolution, Digimon Encyclopedia, or Digimon Himitsu (it's been so long I forgot which site most came from; all but Himitsu are still active and can be found on the Links page). Pictures from the Happy Galgomon Gif Factory will be noted with an illustration credit. Pictures with the Ectozone.net logo, with or without the marking "Illustrated by Veedramon", were ones I made myself.
Family
The background is one of a number of backgrounds inspired by the Bandai card backgrounds, and indicate the broad "family" the Digimon belongs too. Note that some Digimon are considered to be in more than one family; I just picked the one that I personally found appropriate.

Nature Spirits Deep Savers
Nightmare Soldiers Wind Guardians
Metal Empire Unknown
Dark Area Virus Busters
Dragon's Roar Jungle Troopers

Name
With sometimes as many as three choices to make (the original Japanese name, the Bandai USA name, and the Saban/Sensation dub name don't always match) I'll be honest: for my purposes I pick the name that sounds the best for me as the one I'll use.

And it won't be consistant, I will tell you straight off; I may favor the dub names, but I do pick and chose. Examples: I can go either way on Diablomon/Diaboromon...Diablomon is the more accurate translation, but Diaboromon also has a neat sound to me. Goburimon actually sounds better to me than Goblinmon. On the other hand, Deputymon is so retarded a name I'll keep calling him Revolvermon..

Anyway, only my personal favorite name will be in the Codex files that appear in the fan fics (it's part of the jpg after all) though any variants will be noted on the more complete Codex web page.

ID Number
This is an official number used by Bandai USA and Bandai Asia. 001-370 are confirmed from the D-Power software; 371-572 are from a list posted by Seraphimon12 on Digimonccg and other places, drawn from a Bandai Asia list (though some are confirmed in the D-Tector Digivices released by Bandai America). If there's a "---" listed, either I don't know the number or it's a critter of mine or OgreBBQ's own creation, and thus doesn't have an official number.

Within the Digimon universe itself, I tend to think of this as something Koushiro Izumi started to organize his Digimon files, which is why it starts with the Digimon encountered during the first season of the show.

For the full list, go here

Codex Number
This is something completely unofficial--it's essentially a second ID number I assigned myself; it begins at A-01, and progresses thusly: A-01 is followed by A-02 and up to A-99, which is followed by B-00, then B-01, and so on. The earliest numbers are based on the evolutions of the original Digimon virtual pets (ie A-01 is Botamon, A-02 is Koromon, A-03 is Agumon, A-04 is Betamon, and so on), then the first Digimon World video game, then the Pendulum 1-5 virtual pets, Season 1 of the animation, and so on, until around D-50, where they simply become what order I heard about the critter.

An important exception is the series of Codex numbers beginning with "E"--these as a rule mark Digimon that OgreBBQ or myself made up. There are a few cases where a canonical Digimon will have an E number, which means it was a name (ie Orochimon) or an idea (AlforceVeedramon, an alternate Mega for Veemon other than Imperialdramon) we had before we'd heard about the canonical creature, and replaced our concept with theirs.

Within the Digimon universe itself, I justify it with a line of hooey about it being the file transfer protocols on the Yggdrassil servers which house the Digital World or somesuch.

For the full list, go here

Type (Attribute)
"Attribute" is original Japanese term, and is more commonly used, though Bandai USA used the term "Type" for a while, including on the D-Tector, and I've continued to use it so I don't have to go back and redo every single file picture

There are five main attributes: Data, Virus, Vaccine, Unclassified, and Variable.

Data is the most common attribute in the populace at large, and is stereotyped as "neutral" in alignment. Data Digimon are weak against the attacks of Virus Digimon, but strong against Vaccine.

Virus are stereotyped as "evil" Digimon, though two of the most gentle good guys in the series--Wormmon and Guilmon--are technically Virus. Virus Digimon are weak against Vaccine, but strong against Data.

Vaccine in turn are stereotyped as "good guys", though again there are exceptions--Lucemon, the main villain of Digimon Frontier was technically a Vaccine. Vaccine are strong against Virus, weak against Data.

Unclassified usually refers to Digimon of the Fresh or InTraining Digivolution levels; they're too young to truly manifest the Data/Virus/Vaccine attributes yet, though are essentially treated as the same as Data.

Variable is the attribute of the Spirit Hybrids, who have the ability to match the type of their opponents(or, presumably, to shift to the one their opponent is weak against)

Group
This is pretty much a descriptive term, and some are more useful than others--there are about three "Holy Dragon Digimon" and about two hundred "Animal Digimon". The Bandai USA listing of Group is usually used where known, though they tend to be a little more generic.
Level
Level is the extent of the Digimon's Digivolution (Digital Evolution). There are six main levels and two special groups.

(I)Fresh Bandai USA sometimes lumps it into "InTraining", and in Japan it's officially "Baby I". "Fresh" is an unofficial term, but differentiates it from Level (II) better. Fresh Digimon are often depicted as only being able to babble their own name Pokemon-style

(II) InTraining or "Baby II". They're beginning to develop personalities and might have different attacks than the default "Bubble Blow". Specific Fresh Digimon usually digivolve into a specific InTraining, though more recent products have been weakening this rule.

(III) Rookie or "Child". Some of the Digimon's genetic diversity begins to show, as most InTraining have the capacity to digivolve into at least two potential Rookies. Rookies aquire a Type (Data, Virus, or Vaccine) and their Techniques start to be capable of actually causing damage.

(IV) Champion or "Adult"--this is, for the vast majority of Digimon, the highest level they'll ever achieve. Most Rookies have the potential to digivolve into at least two potential Champions; some (ie Agumon or Gabumon) might have dozens. In turn, two Champions of the same species might have evolved from completely different Rookies (Essentially, the Evolution chart is not nearly as linear as those of Pokemon)

(V) Ultimate or "Perfect" In the early virtual pets, this was the highest level possible, and in the Digital World itself was considered the level of "full Digivolution" for many years. Digivolution to Ultimate is not a "normal" event--it usually requires either DNA Digivolution (the fusing together of two Champions, known in Japan as "Jogressing") or an infusion of energy (from either a sigil artifact like a Crest, or the special Matrix energy generated by Calumon)

(VI) Mega or "Ultimate/Final" Creatures of often indescribable power, and thankfully quite rare--Megas have an unfortunate tendency to be corrupted by their vast power (unless they have a human partner to ground them) Some Megas can be created through the DNA fusion of Ultimate, but most must recieve a vast infusion of energy related to the "source codes" (one of the Digicores of the Digimon Sovereign, or certain manifestations of the powers of Hope and Light). A few can Digivolve straight from Rookie to Mega through "Warp Digivolution", or by "Biomerging" with a human.

There are also Megas formed from the DNA Fusion of two Megas, and are sometimes referred to as "Super Ultimates" or "Super Megas". But as of yet, this has not been officially declared Level (VII). "Super Ultimates" are still technically Megas/Ultimate-Finals.

Armor Armor is a special kind of Champion Level Digimon that can be created though the use of a sigil artifact known as a "Digimental" or "Digi-Egg", of which there are nine (Courage, Love, Friendship, Knowledge, Reliability, Sincerity, Hope, Light, and Kindness). There are two more powerful Digimentals, the Golden Digimentals of Miracles and Destiny, which due to their stronger ties to the "source codes" produce Armor Digimon of power more analagous to Ultimate or Mega.

Hybrid Hybrids are Digimon created by the power of a Spirit Totem, which can be used by a Digimon or even a human. There are ten spirit types, based on the ancient elements, and each has a Human and a Beast Spirit Hybrid. In some special cases, the powers of the Human and Beast Spirits can be combined to produce an Hybrid (Fusion), and multiple spirits combined to create a Hybrid (Unity). Hybrids are usually analagous in power to Champions, Fusion to Ultimates, and Unities to Mega Digimon

Techniques
These are the special attacks a Digimon knows, often (but not always) an energy, elemental, or psychic-based attack. They have one Primary Technique, and often Secondary Techniques. Obviously, the average Digimon can still punch, kick, ram, or bite you even if they don't have such an attack listed--if they do, it's gonna hurt a lot more.
Flavor Text
Just a line or two of descriptive nonsense. If a Digimon has a Sigil associated with it, it will appear here. What this means is that the Digimon is an Ultimate or Mega that Digivolved to that level using a Crest (ie WarGreymon), one of the Season 1 Megas who didn't actually appear, but has been accepted as such (ie Phoenixmon has the Crest of Love sigil), an Armor Digimon which uses a Digimental, or even a Digimon that has one of the symbols on their bodies (ie Gallantmon, who has the Crest of Courage on his shield).

The other set of sigils are those associated with the Legendary Warriors in Digimon Frontier

Associations
These fall into two categories:

1. Groups which the Digimon fall into. ie the Royal Knights, the Legendary Warriors, the Seven Demon Lords

2. A DigiDestined or Tamer who was partnered with(or became, in the case of the Spirits) that Digimon. Currently, Digimon from the following sources should be identified:

(Adventure): Digimon Adventure, Seasons 1-2 (both, since they were the same continuity. These are also valid in the Digimon Quest continuity) At present, only the main characters (the "true" DigiDestined) are identified fully. Only a few of the more important tamers (the ones who never had a Crest or a Digimental) are noted.

(Tamers): Digimon Tamers aka Season 3

(Frontier): Digimon Frontier, aka Season 4

(Data Squad): Digimon Data Squad, aka Digimon Savers, aka Season 5

(V-Tamer): The V-Tamer Manga, which featured an alternate universe version of Tai Kamiya

(Quest): Digimon Quest, the fan fic series Veedramon and Ogremon are working on.

Digivolutions
This is a quick listing of the Digimon's known digivolutions; ususally, only three Digivolution Sources and Progressions will be listed--the most common and/or popular (or canonized in the animated series). Exception is made for the Rookies (and one Champion) known to be capable of Armor Digivolution--all known armor evolutions will be posted (ones canonized by the show will be listed as "Confirmed"; all others will be "Conjectural") Warp digivolutions will be similarly marked--most of the Rookies from the animation have an established Mega form even if it never appeared in the anime, and in that circumstance will be listed as "Conjectural"
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