the
absence of calque is now supposed to be a proof that a term is not the right one???
Shares in company capital could be divided in several "classes" according to the rights associated with each class - NO OTHER term is used by Companies house (if THEY don't know the subject matter, I can't imagine who else would!).
I find it a really bizarre method to claim that it's not the right term in UK company law just because "une classe d'actions" is supposed to be a non-existent term in French.
To make it even more bizarre as method, the term "une classe d'actions" DOES EXIST in French (French French, that is) and means "class of shares".
If it happens that not all shares are "the same", then the action capital is divided in "classes (of shares)" makes no difference if classes are designated by letters (for brevity) or by names as "ordinary, preferential, non-voting, whatever ..) - there is no possible "other context" when a different name would be used for different categories / types / varieties of shares.
https://www.limitedcompanyhelp.com/different-classes-shares/