So i thought of a few tags i am somehow missing.. possibly some of them have other year old suggestions already but i start anyway :p
new pet system
instead of common domestic animals are useable by all a new tag:
[PET:*pettag*]
for example
dwarfs and humies get the pettag for the now common domestic, while the old common domestic goes away, elves still get the use any petrace and goblins instead of "use evil pets" get:
[PET:TROLL], [PET:BAT_GIANT] and [PET:WARTHOG] etc.
the pets still use the war trainable, packing animal, milk etc from the creature definition after this
this gives more freedom in modding in civs with their very own array of pets without intersection of the common domestics (like in my drow mod i dont want my drow to use cats, cows and dogs, but spiders, lizards and rothen, while dwarfs shouldnt use those)
slavery is something more or less ingame but cant be achieved in fortress mode. this could be handled similar to the pet tag just [SLAVE:HUMAN] make this entity aviable to get human slaves, even on embark. maybe? but thats not the focus here (please dont rip the suggestion for this part alone :p). if an enity uses slaves they have to decide which size the armor/clothing equip will be of course for the forges and clothier. slaves maybe could try to steal/flee if unhappy and dont see active military nearby. normal slaves cant be in military, but then we can use [SLAVE_WAR:MINOTAUR]. of course pet value need to be viewed at for various entites (like trolls are now 1 buck on embark with the use_evil_pet_race. warslaves behave like normal units in the fort just always go berserk.
so in short: slaves can be used for anything except military, will try to flee and steal if unhappy and no military unit nearby, still throw tantrums, go berserk, etc. if feeling really really bad, war slaves can be used in military but only can use hauling jobs if unactivated.
moveset tags:
we now have amphibian, aquatic, flier and normal.
new tags working similar to flier could be climber, climber_ceiling, levitate and levitate_high
what does this mean?
climber is easy: this unit can climb up walls directly upwards, maybe even items should make this possible (climbing equipment) so you can fit your dwarfs or adventurer to get behind the lines (and also special ops of sieges may use this then to penetrate your defenses from the other side)
climber_Ceiling let them even climb along ceilings and on x/y axis while near walls, this would be useful for animals like spiders.
levitate is just this unit can move one z-level above ground, this also includes the climber tag, as they can use their inherit levitate to easily climb up walls, some megabeasts could use this or ghosts etc. (contrary to just fly aroun everywhere)
levitate_high includes all of the above but they can go straight up without walls too, they just cant move in free air (except 1 z level above ground)
depending on how complicated this would make pathing just climber_ceiling would be enough though (giant cave spider on the wall! ring the alarms
)
underground embark:
some civs are not animal civs but still build cities down there, so a entity can be layer connected without being just small camps. for example again my drow mod: they embark underground, drow towns are underground (but maybe try to build near cave entries for access in adventurer mode)
[always_cave_adapt] tag: more vomit for my drows... so going aboveground is bad any day, any time (except maybe night in adventure mode) not just after staying undergound. unlike dwarfs such creatures can be light adapted, meaning they just vomit less aboveground (instad of all the time) after being there for a long time already. this can be interesting for many nonblind cave creatures and maybe even randomly on forgotten beasts too, as they start vomiting the hell out of it if you lure them aboveground