Right. So constant SMW_FOO_BAR needs to be set in con­figu­ration para­meter $smwgFOObar for a particular feature to be active.
Right. SMW "Administrative functions" returned a bit-flag number.
O wait. I forgot. Without knowing what value what constant uses I still won't be able to figure out if a particular feature is active on a particular wiki. Guess those pages are only intended for (and created by) wiki bureaucrats.
There we go. ... lets save that where its useful ... for me, for later.
Mmm ... no signature button. Guess its added automatically. ... if not, fuck it.

General useful links: (that the SMW-site seems to have hidden away)

(if there was some most badly organized wiki-site competition, this site would get top marks from me)