This list is incomplete and shall be updated and expanded as more related vanilla C# code details are found out and/or as more C# functionality are added.
These prefixes are largely used to refer to pawn-related data. Here's a partial list of elements you can write just after these prefixes.
Most of the entries are self-explanatory, and those I believe to be the main ones are shown in a larger font.
Examples for "faction": Empire, PlayerColony
Possible values: Male, Female.
Returns the higher passion of the pawn. In case of ties, the choice is random among the tied skills.
It's the generic name of a particular job being executed by the pawn. A more specific ID is contained in the related
I don't have the full list - what I know I deduced during debugging sessions.
Here's a very partial list of
BuildRoof, Clean, CutPlant, FinishFrame (build structures), GotoWander, HaulToContainer, HaulToCell, Hunt, Ingest, LayDown (going to lay down/laying down), Pray, Wait_Wander, Research, Skygaze, SocialRelax, Sow, StandAndBeSociallyActive, VisitSickPawn
It's the [-100,100] opinion the INITIATOR has about the RECIPIENT.
For a female pawn, these equal to she, her and her respectively.
For a male pawn, these equal to he, his and him respectively.
It refers to the DefName of a pawn's thought. Listing all the possible pawn's thoughts (even if we just consider vanilla only) would be too long and it's currently out of the scope of this wiki.
Nonetheless, if you wish to find out more details, you can open the XML documents available in the [...]
\RimWorld\Data\Core\Defs\InteractionDefs game folder. You can check other
Defs sub-folders, too, for anything related with the interaction keyword.
thoughtDefName there is a
thoughtText associated, which refers to the description of the thought.
I'm quite sure it's the DLC royal title. I am sure one option is "freeholder".
You can find the whole titles list in the Backstories.xml file. There is no universal path for this, but it's probably compressed in one of the language-specific .tar files.
You could also write XML lines for a specific custom title, and then give this custom title to pawns in your game, so that these will use the title-specific lines. For instance, you could create a specific character called "Pulcinella" and write specific lines for it. Then, while playing, you select a pawn and set its title to "Pulcinella" - this way, the pawn will use the specific lines you wrote.
The full traits list (at least for the vanilla ones) is available here. You can use the names listed there, but with the first letter in lower case.
The full vanilla skill list is: shooting, melee, construction, mining, cooking, plants, animals, crafting, artistic, medical, social, intellectual.
The possible values are:
Checks if the pawn is seating on some furniture. Possibile values are
They must be enclosed in  brackets. A partial list is: AdjectiveAngsty, AdjectiveAny, AdjectiveBadass, AdjectiveFriendly, AdjectiveLarge, Animal, AnimalGroup, Apparel, Color, Community, Enemy, Gore, Mechanoid, PersonJob, Quantity_adjphrase, TerrainFeature, TreeType, Vegetable, VerbFriendly, Weapon
Possible values are:
Possible values are integers between 0 and 23.
This prefix is used with a postfix to return the specified world object type that is nearest to the initiator pawn. Possibile postfixes for now are:
NEAREST_plant returns the nearest plant type object nearest to the initiator pawn.
Checks if the initiator pawn is outdoors. Possibile values are
Possible values are: