Shubin

Some ancient Chinese pillows in a museum of China: http://www.xzmuseum.com/collection_list.aspx?category_id=499

The term Chi Kung (Qigong, 气功) appeared in mainland of China since 1950s, but the term Nei Kung (Neigong, 内功) appeared in China earlier (about 100+ years?) than Chi Kung. Like what mjjbecker mentioned, qigong practices were widely promoted for health reasons among all ages of people including patients. Nei Kung is a kind of Kung Fu to generate the internal forces for martial arts, or a kind of exercise to benefit the interanl organs for meditation, etc.

Sorry, I know nothing about OpenDao. You are right, 70,000 years ago there are no schools yet. If a few schools need a long time to be developed, they would not be simple or easy to learn. Some people collect complaints so they can make better products. Critic information can help other consumers, too. Thanks for the link. From my point of view, they did not understand 性命法诀明指.

Some people can handle multiple schools but not everyone is able to do it. Doing multiple schools at the same time or jumping from one school to another may cause troubles. The book "Taoist Yoga: alchemy and immortality" is not a good translation of "性命法诀明指".

If I do it, I will translated the title word to word from Chinese to English. The title has three words, “性命”，“法诀”， and “明指”, and I will translated the last word to "in plain Chinese".

For Chinese, if they are second generation immigration and they are in the age of 20s -50s, it would be less than 3%? When they get older they might start to learn Qigong or Taichi. For third generation immigration, it may be less than 1%.

It is good to see someone pointed out errors in the book "Taoist Yoga". From my point of view, Charles Luk could not correctly translate the Title of the book of Master Chao Pi Ch'en, and that is a big mistake.

“there is a limited amount of sexual JIng"，is not based on any Qigoing or theory or book, it is based on the life-span of many Kings in the history of China. They had more sex, they died sooner.

Some schools believe that Yuan Jing hides in a location inside of the body. Regular people cannot control Yuan Jing at all.

If we take Yuan Jing as unformed clay, this smart clay can mold itself into many number of shapes, each having their different qualities and uses. Once molded, it may be impossible to remold it again.

Thanks for your explanation. It seems for me that 'Inferior Virtue' and 'Superior Virtue' are not schools.

It is good to see different views, and you may be right. For poems, I do not think any translating tools can do good jobs. For Neidan related poems, It is very hard for any people or professional translators to get a 1,000 years old poem translated 100% correct. BTW, I tried the first poem of《金丹詩訣》with Google Translate, and the result is not too bad. 半斤真汞半斤铅，隐在灵源太极先。须趁子时当采取，炼成金液入丹田。 Half a catty of mercury, half a catty of lead, hidden in the source of Taiyuan. When it is necessary to take it, it will be converted into gold liquid into Dantian.

It seems that in Neidan, Jing to Qi，is 精 to 炁 （not 气）. Some schools of Neidan call Jing as Yuan Jing (元精), why they do not call it "sexual energy" (性精）？

"used paper copies of Dictionary and Shuowenjiezi " -- very impressive!

It is hard to find a high-quality, semi-contemporary teacher/literature on Taoist teaching/philosophy. If you can read Chinese, there are some articles and videos at https://zhuanlan.zhihu.com/c_167929717 .