Java:
	- the Java UBF doesn't deal with rpcError
	- the IRCClient expects the wrong response to a 'nick' message

UBF-A:

	- escaping of quote characters needs to be formally defined
		- for `...` and %...% and '...'
		- it is defined as expected in the HTML for all three, it
		  turns out; just not in the paper (?).
	- can semantic tags be nested? eg. 3~abc~`example``test`$
	- definition of lists lacks a final "&"!
	- semantic tags might benefit from being registerisable

	- basically, a formal specification would be handy.

UBF-B:

	- bin() vs. binary() - which is it? The spec differs from the
	  examples.
	- term() not mentioned in the right place
	- no support for semantic tags!
	- needs to support importing, or inclusion, or something - so
	  that *types* can be shared between contracts
	- need to have a contract defining the "contract" type!
	- tokenizer specification required.

UBF-C:

	- half-reverse-engineered... better documentation urgently
	  required