This is from Ñanavira’s book Notes on Dhamma:

(There is no doubt that images are frequently made up of elements of past real [five-base] experience; and in simple cases, where the images are coherent and familiar, we speak of memories. But there are also images that are telepathic, clairvoyant, retrocognitive, and precognitive; and these do not conform to such a convenient scheme.

I don’t see how the definitions of scheme fits with ‘images are frequently made up of elements of past real [five-base] experience;’. How is such a thing a scheme?

Does ‘such a convenient scheme’ mean ‘a convenient scheme like this’?