ATTACK = Basic attack value
HITS = Hit Points
MOVES = Movement rate (see UNIT_MOVE_SPEED in rules.xml)
SUPPORT = Ramping cost of unit (f=food,t=timber,m=metal,g=wealth,k=knowledge,o=oil)
COST = Base cost of unit (multiply by 10) (f=food,t=timber,m=metal,g=wealth,k=knowledge,o=oil)
PREQ0 = First prerequisite (always absolute)
PREQ1 = Second prerequisite (if a Library "color" tech, this is scaled based on the starting/ending Ages of the scenario or encounter)
PREQ2 = Third prerequisite (always absolute; if from same color column as PREQ1, only the more stringent of the two will be used.
FROM = Previous unit in upgrade line (which this unit upgrades from)
GRAFT = Sideways grafting for unique units (indicates the mainline unit for which this is a unique substitute)
RANGE = Minimum and maximum range of weapon (in "TCoords"; 1 WCoord = 4 TCoords = "One Farm" in width or height)
LOS = Line of sight, in TCoords
SCIENCE_LOS = Additional line of sight per science technology researched; use sparingly, it's CPU-intensive.
FLY_HIGH = Air units "fly high" while moving from base to target, not yet engaging. For anti-air unit to hit air unit it must roll within it's own FLY_HIGH percentage. For non-anti-air unit must ALSO roll within it's -own- FLY_HIGH percentage.
FLY_LOW = Air units "fly low" while engaging a target. For anti-air unit to hit air unit it must roll within it's own FLY_LOW percentage. For non-anti-air unit must ALSO roll within it's -own- FLY_LOW percentage (two separate % checks conducted; if either fails shot misses)
RECHARGE = Recharge time of weapon in 1/15sec. These times are carefully synchronized with the unit animations times (e.g. guys reloading cannon, or whatever), so changing these values should be coordinated with art department.
ARMOR = Amount subtracted from incoming damage to unit (in most cases unit must always take at least one point of damage; exceptions include non-anti-air vs. air, and "rifleman vs. battleship", etc)