He mentions this version of broad categorization (of self versus mutual) in some of his references, such as one of his letters to me which I shared at EnergeticForum (since he gave permission)...

https://drive.google.com/file/d/0B8FRm7LqRgoaZjdjUVFFaWJuWUE/edit?resourcekey=0--wv9BsxJgbgFucmHclWl0Q

...and is repeated at gestaltreality...

https://www.gestaltreality.com/energy-synthesis/eric-dollard/metrical-dimensional-relations-of-the-aether-by-e-p-dollard/

...while elsewhere he mentions something else, entirely, on page 52: longitudinal versus transverse...

http://tuks.nl/pdf/Eric_Dollard_Document_Collection/Theory%20of%20Wireless%20Power%20by%20Eric%20Dollard_OCR.pdf

What do you think longitudinal versus transverse are equivalent to?

...and, here, he makes no distinctions...

https://web.archive.org/web/20130707134116/http://www.energeticforum.com/renewable-energy/1631-peter-whatever-happened-eric-p-dollard-22.html#post170386