It isn't a strict category like that. It is more like an indicator of the general font lineage the designer considers it to be in. But plenty of sans fonts hav

It isn't a strict category like that. It is more like an indicator of the general font lineage the designer considers it to be in. But plenty of sans fonts have a handful of serifs, particularly on the mistakable chars like l. And especially if they're expected to be used in technical contexts or as an "everything all the time" font like this one.