You're not nesting DATA; you're using DATA as part of your data...
'Star Trek Dudes
DATA Spock, Doc, O'Hara, Data, Blah blah blah...
Now, since quotations aren't required with the DATA statement, the above is going to count Data as user data and not a command. The same is happening with your code: DATA 00001011 is simply being read as an user string of data consisting of "DATA 00001011"...