While reading up on the Diffwys wharf, Maentwrog and Tyddyn Isaf further down the Dwyryd then searching the "Port" category. Felinheli was the only one showing up (restricted to SH). That made me wonder... When populating the "type" was it intended that wharfs and Quays be lumped in with ports?
I suppose it's a bit like differentiating railways and tramways perhaps?