To ask what this means...

[MrsGriff8]

I'm quite new to this so please be gentle... bit what does this:

mean? Seen it on a few threads. Thank you!

It's a biscuit. It means someone likes you and agrees with what you're saying.

'have a treat on me' type thing.

Nope! Definitely not someone agreeing with you and liking what you're saying. The exact opposite in fact.

@forzaH 😂😂

It's derogatory. Like "you just wrote the most idiotic statement and I can't even be arsed to explain why"
That's what I've come to learn it means

It's shorthand for "You take the biscuit"

It's a biscuit?! Haha I always thought it was a precious flower.

I can see the Jammy dodger now

It's when someone or something is very annoying or bad.
On MumsNet the equivalent is usually referred to as "Cheeky Fuckery"

But some people misunderstand it and think it's an actual biscuit to give someone as a sort of reward.

Unlike the coffee or brew icon which is offering someone some comfort.

Mumsnet is complex.

It originated from 'Biscuitgate' where the then Prime Minister, Gordon Brown, repeatedly ignored and refused to answer the question of what is his favourite biscuit in a Mumsnet Q&A.

It's meant to mean 'No comment', a refusal to engage (especially when OP is being goady/trollish/outlandish).

Aah ok, makes sense! Thank you!

No worries