ga_rune_pose is just the name I was saving my Rune OP parody images under, and so I just started tagging things with it here too (after telling people and saying I was open to a better name of course). It's only for the OP parodies - the lineup of characters against that background as they do in the series opening animation - not the keep_out caution tape.
Think of it as the Rune equivalent of motteke_serafuku.
