[elemeno]

That only applies if the criteria in 101.1.a.4 are met:

  (4) Except as provided for in 101.7, any unmanned free balloon
 that-
     
     (i) Carries a payload package that weighs more than four pounds and
     has a weight/size ratio of more than three ounces per square inch
     on any surface of the package, determined by dividing the total
     weight in ounces of the payload package by the area in square
     inches of its smallest surface;
     
     (ii) Carries a payload package that weighs more than six pounds;
     
     (iii) Carries a payload, of two or more packages, that weighs more
     than 12 pounds; or
     
     (iv) Uses a rope or other device for suspension of the payload that
     requires an impact force of more than 50 pounds to separate the
     suspended payload from the balloon.
     

As long as those don't apply to you, you're pretty much good to go. I'd imagine that they're criteria where, should your ballon hit anything, it wouldn't cause any damage.