What is the source of these "Lay Bodhisattva Vows"? Okay, I'm well familiar with the regular Bodhisattva vows from the Brahma Net Sutra. That set of vows is open to both lay and monastic followers.

I just found another set on Dharma Realm Buddhist Young Adults and I can't figure out where they come from (which sutra).

Full text linked below. It has 6 major and 28 minor precepts. It has precepts like, 21st-- pay your taxes and 27th-- don't raise silk worms.

Is this a modern set of precepts or does it have a older origin?

ref: 
http://www.drby.net/attachments/035_The%20Bodhisattva%20Precepts%20for%20Laypeople%20-%20English.pdf

(Above PDF came from this link: http://www.drby.net/index.php/Events/Lay-Bodhisattva-Precepts-Transmission.html )
Okay I found the answer. 

It's from the "Sūtra of the Upāsaka Precepts" (Shansheng Jing). It was translated into Chinese in the 5th century. 

http://www.sutrasmantras.info/sutra33c.html

This sutra has similarities to the older Sigalovada Sutta http://www.accesstoinsight.org/tipitaka/dn/dn.31.0.ksw0.html

(Ref comparing the UPS and Sigalovada: "Buddhism and Peace", chapter 10)