At the Africa Regional Conference on Fistula and Maternal Health, more than 150 people from 40 countries and partner organizations met in Mauritania to better integrate fistula care into existing national health care systems.

VOA: standard.2009.12.23

It's the study of existing, conventional, communicative systems.

它是关于现存的，常用的，有交流功能的系统的研究。

耶鲁公开课 - 文学理论导论课程节选