Hi @lowercase
You can query the posts and find the ones which have ‘YES’ by reading this tutorial:
http://www.advancedcustomfields.com/resources/how-to/how-to-query-posts-filtered-by-custom-field-values/
@smspaul – thanks for your help, however the thread you linked to is not related to querying posts, it is regarding loading a radio field value.
Thanks
E