Boring one about tumble dryer symbols

[MinniesAndMickeysNeedCounting]

I've just been given some clothes and they have a tumble dry symbol I haven't seen before. They're childrens clothes from m&s.

It's a square with a circle inside, that's it.
Usually they have dots for low/high heat or a X through it.

I've looked it up online it just says 'tumble dry'

I think it might mean tumbling is actually recommended.

Wrong again!
I guess better to use low temp though.

It just means the item can be tumble dried - and if it's a square with a circle and a cross, then it can't be tumble dried.

I tumble on low unless it's towels or bedding.

Thanks very much.
We were thinking dry on low cause it would have had a cross if not suitable but seemed such an ambiguous symbol.

Knew MN would be the fastest way to find out.