Collecting data on all living characters as of APRIL 11, 2017. Please do not include any characters dead before this date or born after this date. Participation is not required, but encouraged. Include all your characters if you can. Results will be published when a large enough sample is collected.

How heritage is determined
Even if you are born and bred in your Clan, with parents born and bred in your Clan, that doesn't necessarily make you pure-blooded. Below, we explain some stipulations.
Clan jumpers
[example] Squirreltail, a pure-blood ThunderClan warrior, leaves ThunderClan to join her mate in RiverClan. Her mate is Minnowstripe, a pure-blood RiverClan warrior. They settle down and have kits. Their kits are considered half ThunderClan and half RiverClan. It does not matter that both parents now live in the same Clan—this is still considered crossbreeding.
Exiles
[example] Toadstep, a pure-blood ShadowClan warrior, is exiled from ShadowClan and begins life as a rogue. He has kits with a kittypet named Miss Flufflekins III. Their kits are considered half ShadowClan and half kittypet. It does not matter that Toadstep is now a rogue—he is still considered a pure-blood ShadowClan cat.
Orphans
[example] Harefang was part of a rogue litter abandoned in the moor as a kit. He was found by a WindClan patrol, adopted by a WindClan queen, and raised as a WindClan warrior. He has spent his entire life, as long as he can remember, as a WindClan cat. Harefang is still considered a full rogue for all intents and purposes.
SkyClan
SkyClan was driven to near-extinction many generations ago, whereupon they disappeared from the forest. Silentstar, the last of SkyClan, left her kit (Lavenderheart) to be raised in WindClan. Lavenderheart had kits of her own, continuing SkyClan's bloodline. Silentstar later returned to the forest, having rebuilt SkyClan from a group of rogues, loners, and kittypets, and had another kit, Silverstorm, who also had kits of his own.

This means there is no such thing as a true pure-blood SkyClan cat... at least, in these territories. While true SkyClan blood still lingers, it has been heavily mixed with outsiders, otherwise it would've died out. If you are, for all intents and purposes, a "pure-blood" SkyClan cat, list yourself as tainted blood.

Blood classification
Pure blood
Your bloodline is untainted by outsiders. You can track your family tree back to its roots without finding any trace of rogue, kittypet, loner, or rival Clan ancestry. You and all your forebears have all belonged to the same Clan as long as anybody can remember. If you're unsure of your complete family tree, if all four grandparents are listed as pure blooded, then this is likely the case for you.
Tainted blood
Somewhere down the line, more than four generations back, a direct ancestor crossbred with an outsider. The impurity lingers in your bloodline, but is far removed from the current you. If you are only 1/16 "impure" or less, then you belong to this class.
Mixed blood
There has been crossbreeding in your recent family history. If any of your parents, grandparents, or great-grandparents bred with an outsider, then you are considered mixed blood.
Outsider blood
You are a rogue, kittypet, or loner, with not a drop of Clan blood in your veins. In a sense, you're pure-blooded in your own way.

Here's the template

Code:

[b]Name:[/b]
[b]Creation:[/b]
[b]Clan:[/b] (include birth Clan as well if different from current Clan)
[b]Mother:[/b] (include purity and Clan)
[b]Father:[/b] (include purity and Clan)
[b]Class:[/b]

Name: Yewkit
Creation: https://warriorclancats.forumotion.com/t27288-yewkit-of-shadowclan
Clan: ShadowClan
Mother: Ravenclaw of ShadowClan (tainted blood)
Father: Sleetfang of RiverClan (pure blood)
Class: Mixed blood