You see it on MN when a poster, out of seemingly nowhere, calls someone racist and at first pass it makes no sense until you remember they’re not really talking about the royal family at all.
But there is, objectively, a lot of racism on Mumsnet, and a history of racism on Mumsnet.
There's also a lot of posters who seem to have an agenda to deny that racism exists at all, or who want to shorhorn black people pushing back against racism into their "anti-woke" ranting, or who want to discredit black Brits from speaking about their personal experiences of suffering racist abuse by randomly bringing up Critical Race Theory in America in weird and inappropriate places.
There are unfortunately a lot of posters who think racism begins and ends with black people being lynched, and that anything less than that doesn't count as racism and is just "wokesters" trying to "virtue signal" by "playing the race card." (All accusations that are constantly thrown about here towards black posters).
Black posters are far better attuned to recognising racist microaggressions, dog whistles, and coded racism.
But I understand that to a white person on a forum where blackface and golliwogs are excused as innocent fun, BLM protestors are called thugs (while white supremacist protests are met with dozens of "I don't agree with their principles but I support their right to protest due to free speech"), George Floyd was called a thug and had his whole personality and life trashed, Ahmaud Arbery's murderers was defended, posters share hilarious anecdotes about their children asking why a black man looks like chocolate, threads expressing outrage whenever a black actor is cast in a white role, comments like "why are black people allowed to say n***r but we're not", black female celebrities consistently being trashed and demonised, black posters were attacked for wanting a Black Mumsnetter section, just the constant drip drip drip of barely disguised racism that unfortunately has permeates this forum in the past.
Yeah, I can see why a white person in a culture of systemic coded racism would be confused by black people being able to recognise racism that they personally cannot see.