From what I read about marking in UK schools suspect that this is of very little use to anyone else, we aren’t ofsteded so I’ve no idea what they’d think.
Our school sends home regular updates with a level (yes we still do levels) and an effort grade from 1(good) to 5(so poor it is very rarely given). Parents are often less concerned by the level than by the effort grade, and so we have to be prepared to justify it to them and to the SLT. With this, and the idea that kids only read their grade and not the comments, in mind (boys don’t tend to be competitive about the amount of work they put in!), we stole an idea from our Maths Department, which has since spread to other departments. The idea is that homeworks should only be graded on their effort (ie 1 to 5) and that it should be the ticks and crosses and comments that convey how the Physics went. It is a lot easier to judge effort than level on single piece of work. Then a mean of the grades received since the last report home can be the easily justified effort grade on the next report home. It also means that boys in lower ability groups do not have to consistently get low grades. It has worked remarkably well, marking is much easier and when, as is quite often the case, our grades that are sent home are questioned as harsh we have our justifications ready.
Of course if you are going to go in this direction you have to make sure that you have documentation explaining your expectations in place, and so the following document is on our VLE, for the boys, but mostly for the parents: