Open Coding?

I came across this phrase in Deborah Brandt's article "Writing for a Living":

I used open coding (Strauss, 1987; Strauss & Corbin, 1998) to track all descriptions of work processes and materials, genres, audiences, voices, teaching and learning on the job, solicitation of writing by oth- ers (i.e., clients or customers), uses of workplace resources beyond the workplace, and workplace contact by family members as these descriptions were invited directly by interview questions or arose implicitly or explicitly in other parts of the interview.

The citations are:

Strauss, A. L. (1987). Qualitative analysis for social scientists. New York: Cambridge Uni-
versity Press.

Strauss, A. L., & Corbin, J. M. (1998). Basics of qualitative research: Techniques and proce-
dures for developing grounded theory. Thousand Oaks, CA: Sage.