Help understanding these sentences

I believe what they are referring to adaptive immunity.

We each have millions of kinds of B + T cells with different antigen receptors just waiting to be activated inside of our lymph. Our immune system randomly generates these and are stored in our lymph nodes. Once an antigen binds to such b-cell, the activated b-cell produces thousands of clones for that specific antigen. Anyway, you know the rest.
 

what do they mean by "pattern"?


for example

"Most geneticists and immunologists would probably prefer to look for randomization of pattern in a hypermutability of one or more genetic loci at some stage during em- bryonic life with a relative stabilization subsequently. This is in line with the general dogma that the pattern of a protein is determined in the last analysis by the pattern of a segment of chromosomal DNA".

"There are two ways at least in which the functional elimination of patterns reactive with self components could be implemented. If a cell or clone is limited to one or two patterns, then it is practical to postulate that any clone".

They keep mentioning pattern but i do not fully understand what they mean by saying "pattern"

Pattern of the variable region of antibodies