I can try.

Auto-antibodies specific for the acetylcholine receptor are measured by running a serum sample in an immunoassay. Various different types of immunoassays can be used.

There are two parts to the output; the result (its numerical value does not necessarily mean anything) and the reference range (the range over which the result is considered normal)

Looking at the image that you posted above, the reference range is defined but I am not sure about the "20" in it. It might just be a code number or it might be the result.

If you want to get more details from the lab which ran the immunoassay, I can interpret them for you.