So confused by the lack of hover text… :-)
Possibly because I have a FireFox extension just for those, actually: http://piro.sakura.ne.jp/xul/_popupalt.html.en
Anyway, thanks Randall and Mr Bill!
Mr Bill has an entirely different meaning to those of us who watched Saturday Night Live back in the 1970s. https://en.wikipedia.org/wiki/Mr._Bill