Understanding Society User Support

Dear Understanding Society Team,Dear All,
I am trying to with the Understanding Society data wave 2. I am mainly interested in differences between ethnic groups.

I have a problem when using wave 2 and I am wondering if I am doing something wrong. The data documentation (user guide etc) did not help me at all with this, nor does emailing info@understandingsociety.ac.uk . The only response I received was to post my question here, and the response was not signed by a person. I'd be really grateful for any help!

I am interested in the individual level, not the household at this point. So I am using the b-indresp data file. I am trying to use the ethnic booster sample in wave 2. When requesting the frequencies of the household origin variable, the the output tells me that 5598 respondents are members of the ethnic booster sample.
However, when I then request the frequencies for the ethnic group indicator variable b_racel , then I get the following: 46811 respondents are in a category called ' inapplicable' and 3882 respondents are in a category called 'proxy'. However, the numbers of respondents belonging to each ethnic category of that variable (b_racel) are far too small, they are nowhere near the 1000+ respondents that (according to the userguide) were sampled for each ethnic group.
My questions are thus:
1. what does the category ,inapplicable' mean? Who is in that category and why is this category part of the ethnic minority variable? (this category is not part of the ethnic minority variable in wave 1). Unfortunately I did not find the answer in the data documentation.
2. what does the category 'proxy' mean?
3. where is the ethnic booster? How can I get the ethnic booster and what do I need to do to obtain the numbers of respondents belonging to each ethnic group using the 2nd wave of 'Understanding society'? How can I get the numbers of respondents belonging to each ethnic group? Requesting the frequencies of variable b_racel does not work.

I can get the ethnic booster without problems in wave 1 but not in wave 2.

Many thanks in advance for your help.

Best,
Stef