Inside the w3m/w3x (the 2nd)

ECA Structure

int: ECA type (0=event, 1=condition, 2=action, 3=call)
optional if this is not a top-level ECA
  int: branch (0=if-conditions, 1=then-actions, 2=else-actions, if the parent is not an if/then/else this will be 0 because there's only one branch)
string: name
int: enabled (0=disabled, 1=enabled)
  "x" times a parameter structure (where "x" depends on the number of parameters defined in TriggerData.txt)
int: number "n" of children
  "n" times an ECA structure (when parsing these child-ECAs we need to read the additinal branch-int mentioned above also)


Parameter Structure

int: Parameter type (0=preset, 1=variable, 2=function, 3=jass)
string: value
        = preset name if paremeter type == 0
        = variable name if parameter type == 1
        = default display value when function is not found in TriggerData.txt if parameter type == 2
        = jass string if parameter type == 3
int: functioncount "fc" (usually 0, only for parameter type is function it's 1)
  "fc" times an ECA structure
int: arrayindexcount "ic" (usually 0, only if parameter type is variable and the variable is an array it's 1, as long as Blizz doesn't decide to invent multidimensional arrays it's safe to assume this can't be higher than 1 - lazy bastards)
  "ic" times a Parameter structure