Thanks navylad, appreciated.

I probably should have highlighted that more and it's in a sub section in the first link in post 2 (non-visible disabilities)

Here's what BA states:

Sunflower lanyard

The sunflower lanyard is a UK airport authority initiative designed as a subtle way of indicating someone has a non-visible disability and may require some extra assistance. As an airline we have embraced this symbol and are keen to promote the benefits it can bring to our customers.

Lanyards are available at all participating airports and can be collected from Airport Assistance. For our customers travelling from London Heathrow, you can order your lanyard to be sent to you by post before you travel. At the moment the lanyards are a UK initiative, but they are starting to be recognised internationally in some destinations.

https://www.britishairways.com/en-gb...ance-available

Pete