I think more thought should have gone into drafting the poster, to give clearer guidelines as to what is deemed acceptable. So with that in mind, it could have been displayed thus : A "selective" diversity day, discretionary preclusions may apply and they could have been listed along the lines of:
No Union Jack, St George's flag of England, Welsh national flag, and please don't incorporate these into your costume, you may wear a small tartan scarf though
no don't ask why, even we can't answer such an anomaly Then other exclusions quite obviously would be dressing up like a Pearly King or Queen, A Chelsea Pensioner, A Beefeater, A Morris Dancer, do you ever wonder why they never get themselves on Britain's Got Talent, cos dancing round a maypole with some jingly, jingly bells attached to your person is like well uncool. Please no random Kings like Harold, with an arrow sticking out of his eye, or Charles 1, carrying his head, because missing heads, it's kind of reminiscent of some of the cultures we do wish to celebrate. Most of all no Lord Kitchener or Churchill or any other of
them those badass guys, talking of which, do not under any circumstances come in trying to emulate a typical English toff such as Jacob Rees-Mogg, and certainly don't come in speaking like him or in Dick Van Dyke Londonisms for that matter. If you want to represent London patois, maybe we could suggest, grime or drill artists, although we pledge you don't edge into any sort of rap like speak that extol the virtue of knocking off the people who get the most house points. A softer approach for all you
left behind white boys, may we suggest find your inner drag artist, go the full glitter, remember to ask mum if it's ok if you can help yourself to her lippy, nail varnish, hair extensions and vertiginous heels.
Please note those who would wear their English and Welsh nationalism overtly. This day is not about you!!!