Transducer Manipulation: What is "Tilt", "Rock", or "Angle"?

There seems to be a confusion in this area. For example, when you open up a textbook of echocardiography, one term may be explained in a completely different way from another textbook of POCUS. I once had a heated discussion with my colleague about the definition of each term since I learned from one textbook, whereas I believe he got the information somewhere else and to confess, now I believe he was right, and I was wrong. So where is the "GOLD" standard? The American Institute of Ultrasound in Medicine (AIUM) published a statement in 1999 where they define each maneuver, which could be used as a "GOLD" standard.

AIUM technical bulletin. Transducer manipulation. American Institute of Ultrasound in Medicine. J Ultrasound Med. 1999 Feb;18(2):169-75. PubMed PMID: 10206813.

American Society of Echocardiography has recently published an article on how to perform a comprehensive transthoracic echocardiographic examination, in which they also specifically define these terms which are essentially the same with AIUM.

Mitchell C, Rahko PS, Blauwet LA, Canaday B, Finstuen JA, Foster MC, Horton K, Ogunyankin KO, Palma RA, Velazquez EJ. Guidelines for Performing a Comprehensive Transthoracic Echocardiographic Examination in Adults: Recommendations from the American Society of Echocardiography. J Am Soc Echocardiogr. 2019 Jan;32(1):1-64. doi: 10.1016/j.echo.2018.06.004. Epub 2018 Oct 1. PubMed PMID: 30282592.

The video below (I have found it on YouTube) might be helpful for you to understand the difference between each maneuver.