Understanding Society User Support

Hi!
The scwhoru* variables in wave 5 have strange value labels with @ inside, for instance:
1 @bvery important@b to my sense of who i am

There is also something a bit odd about the don't know responses to this variable, as far as I can tell at least. The question was given to those who agreed to self-completion OR telephone mode. There are two values for "don't know": -1 and 8. Only those who are scflag==1 have -1 values. But they also have 8 values for don't know/doesn't apply. So I am not sure if I should collapse -1 in the 8 category, or treat it as missing. Here an example:
tab scwhoruedu indmode if scflag==1, m

| individual
    important who you | mode type
       are: education |       f2f |     Total
----------------------+-----------+----------
              missing |        11 |        11 
              refusal |        30 |        30 
           don't know |        18 |        18 
bvery important@b to |     9,182 |     9,182 
@bfairly important@b  |    14,962 |    14,962 
@bnot very important |     7,370 |     7,370 
@bnot at all importan |     2,698 |     2,698 
don t know/doesn t ap |     1,928 |     1,928 
----------------------+-----------+----------
                Total |    36,199 |    36,199

. tab scwhoruedu indmode if scflag==0, m

important who you | individual mode type
       are: education |       f2f  telephone |     Total
----------------------+----------------------+----------
         inapplicable |     3,770         29 |     3,799 
              refusal |         0          3 |         3 
bvery important@b to |         2        367 |       369 
@bfairly important@b  |         3        451 |       454 
@bnot very important |         2        150 |       152 
@bnot at all importan |         2         56 |        58 
don t know/doesn t ap |         1          6 |         7 
----------------------+----------------------+----------
                Total |     3,780      1,062 |     4,842

There are also a handful of cases with no telephone and no SC who have values, and they shouldn't I don't think, but I'm not worried about extra cases.

thanks for your help
Renee