Event command bug: add_team_research_type

When I use add_team_research_type to add one specific skill to one team, the game will add mechanics instead of artillery.
Ernst Udet, Ger air-doc team.
event={
id=100000000
random=no
country=GER

name="test"
desc="test"

action_a={
name="test"
command={type=add_team_research_type which=11 value=artillery}
}
}

So theoretically he should have an artillery.