BBcode practise grounds

(define(eval exp env)(cond((self-evaluating? exp) exp)((variable? exp)(lookup-variable-value exp env))((quoted? exp)(text-of-quotation exp))((assignment? exp)(eval-assignment exp env))((definition? exp)(eval-definition exp env))((if? exp)(eval-if exp env))((lambda? exp)(make-procedure(lambda-parameters exp)(lambda-body exp)
                         env))((begin? exp)(eval-sequence(begin-actions exp) env))((cond? exp)(eval(cond->if exp) env))((application? exp)(apply(eval(operator exp) env)(list-of-values(operands exp) env)))(else(error "Unknown expression type - EVAL" exp))))

>>61
"<code></code>" -> ""

i.e. remove empty tags?  Doesn't sound like a good idea to me, BBcode programs can change their output if you remove empty tags.