[R] Filtering output

[rkevinburton at charter.net]

I have a command which returns a data fram if I am not mistaken:

sc <- split(x, list(x$Category, x$SubCategory), drop=TRUE)

Now I wish to get the Category and SubCategory that the data was split on. So my first attempt would be:

 sc[[1]]$Category[1]

But that yields

[1] (Unknown)
46 Levels: (Unknown) 10" Plates 7" Plates   (Dessert) ... WOMEN

Is all I want is '(Unknown)'. I am not sure what 'levels' are and hence they have no meaning to me and I would like to filter that out. Any ideas?

Thank you.

Kevin