[scxml] invoke tag

Hi,

from reading the specification to understand what i am allowed to use an invoke in
the onentry/onexit blocks:

1) 3.9.2 Children (of onentry)
states that they consist of executable content as defined in 3.12 Executable Content

2) 3.12 executable content notes that

" 4 External Communications Module, 5 Data Module and 6 Script Module all define
additional elements of executable content beyond those listed here."

3) in 4.3 invoke is defined as part of the External Communications Module

thus, i can call invoke within onentry/onexit ?

Further on i could define a custom action in a separate namespace like
<my:invoke>  within
onentry/onexit, right?

Thanks,
Sebastian