Xuan Kong Fei Xing system which spreads to the West and whole world since 1990’s; is classified under invention of Master Shen Zhu Reng 沈竹礽（A.D 1849－1906）, approximately 100 years ago ONLY. The West now starts to question how true and how reliable this system in relation to feng shui audits.
If you ask experince feng shui masters, especially those who can read and understand Mandarin/Chinese Classics in our part of the world (active in Asia), they will not hesitate to share their view about the limitation and defections of XKXF, which belong to the school of Master ShenZhu Reng 沈竹礽（A.D 1849－1906）.
The validity and authenticity of XKFX Master Shen has been questioned and studied in East Asia by 90’s and now, turns into a focus of academic discussions among feng shui experts in international level.
There are a few areas which make XKFX of Master Shen Zhun Reng沈竹礽（A.D 1849－1906） which has been highlighted in Mandarin world of feng shui. A few points would be highlighted and be translated for your information.
XKFS of Master Shen is only 50% of whole system of Xuan Kong. (Personally I think it is much lesser than 40%).
The reason is that Shen was NOT the REAL Lineage.（It was a very sensitive issue how he got the system… you could find out yourself）
This system only applicable under certain circumstances, the conditions MUST present are as below
1) Water in front, and Mountain at the back；
2） Justification of Good or Bad Feng Shui which is limited to ONLY FOUR TYPES;
3) The System is PURELY based on 2 PARAMETERS for its theoretical framework which are FACING & SITTING Only.
In Fact, All these 4 types of Interpretation by XKFS could lead to Wealth, Many Offsprings; at the same time these also could be Bankruptcy or Misfortune to the descendants.