Matmatronch search type on certain fields
The matmatronch search is done using __icontains on every field. It is not appropriate on fields such as promo where a search of "9" will return results in promo 9 and 19. 19!
icontains is also not necessary on some other fields, such as role or department (which are enums). Not sure if it matters though. The only aspect I can see where it might change something is performance. Do we care though (micro-optimisations, etc.)?
See matmat.views.SearchFormListView::get_queryset().