Disciplinary Literacy Definitions

Since some scholars do not seem to see disciplinary literacy (DL) and content area literacy (CAL) (I’m going to throw in interdisciplinary studies too) as different ways of thinking about literacy, I decided to collect definitions of DL to help me understand it all.  
Eyes on Disciplinary Literacy” by Vicky Zygouris-Coe
“Disciplinary literacy…emphasizes the knowledge, skills, and tools of the experts in each discipline--the mathematicians, historians, authors, and scientists who communicate, use, and create knowledge in their respective discipline. Disciplinary literacy is not about a set of strategies we can use to help students organize text or make connections among words; it is referring to the ways of thinking, knowing, and doing that are consistent with each discipline.”
Wisconsin Department of Public Instruction
“The Wisconsin Department of Public Instruction defines disciplinary literacy as the confluence of content knowledge, experiences and skills, merged with the ability to read, write, listen speak, and think critically in a way that is meaningful within our content area.”

"What is Disciplinary Literacy and Why Does it Matter?" by T. Shanahan & C. Shanahan
“Disciplinary literacy… is an emphasis on the knowledge and abilities possessed by those who create, communicate, and use knowledge within the disciplines” (p.8). (2012).  see Topics in Language Disorders, 32(1), 7–18.
Do you see DL, CAL, and interdisciplinary studies as separate approaches to literacy instruction?