How to Understand Access Conditions in Mifare Classic 1k

Question

I am working with Mifare Classic 1K, and so far I have successfully inserted/updated data in each block using key A with default access byte FF0780.

I am trying to understand the documentation, but I am struggling. My goal is to modify the access so that both key A and key B can be used for authentication, where key A is for read access, and key B is for full access.

These are parts of the documentation that I cannot understand, especially regarding C1, C2, and C3. Why it show like 001, 000, 111, etc, where this value come from?

In that section, for example, at byte 6, there are references to C23 and C13, both pointing to Sector 3. This is confusing to me. And below is ACCESS BITS ANALYSIS EXAMPLE, Block(3)(Sector Trailer) that show C1 = 0 C1(3), C2 = 0 C2(3), C3 = 1 C3(3) which is not match with the table 4.4

I hope someone can help me understand this. Thank you.