Question about the db file in SQlite

For editing and reference purposes I have been poking around the db files using SQlite. I exported the columns to csv and having opened up only the books.csv I don't know what else I am going to be wondering about, but right now I have to know...what is the "flags" (K) column? Also, the lccn?

Would be nice if there was a chapter in the manual that defined the columns.