Making amends: why do patents and trade marks differ?

Unless you work for the
popular press, it's not hard
to tell a patent from a trade
mark.  What's more, they
even behave differently
From the IPKat's learned friend Douglas Campbell (Three New Square) comes a question which, this Kat confesses, he has never really thought about at all until now. Douglas explains the context of  his query as follows:
"If you are amending a patent in UK legal proceedings, and the amendment in question involves rewriting of claims rather than deletion of existing claims, the received wisdom is that you have to apply for your amendment before the trial or else you’re too late. See eg Terrell on the Law of Patents 15-99 to 15-111, and in particular 15-111 (deleting existing claims after trial is never a problem, because the existing claims have always been there and the public has always known about them).

However in UK Intellectual Property Office trade mark proceedings, you can wait until after you’ve lost (at first instance or indeed on appeal) and then you can have another go at reformulating a trade mark specification de novo. It’s not just a blue pencil test.  Moreover you are positively encouraged to wait until the Hearing Officer actually makes a decision – see Tribunal Practice Notice (TPN) 1/2012, section 3.2.2, here. There does not seem to be any advantage for the applicant in proposing a more limited specification in advance of the hearing, and doing so may be seen as a sign of weakness.

I appreciate that in the patent case Terrell refers to the situation “Where patent is found to be wholly invalid”, but this isn’t literally correct since, if so, then you wouldn’t be able to amend at all (because the patent would be wholly invalid). In fact they are both talking about the same case – ie the claim/specification which you currently have cannot be supported, but some narrower version of it could be.

So how come we have ended up with completely different approaches to what should be the same problem? Is it just because one set of rules has been made by judges and the other by trade mark examiners, is it because amending patents is much more complicated then amending trade mark specifications, or what? And should this continue to be the case?"
This Kat has given some thought to the question and thinks that the explanation may be based more in the random factors of legal evolution than in specific intent.  Since patent amendment practice and trade mark amendment practice were, at least in their early days, generally dealt with by different people with different skill sets, under different legislation and without regard to the fact that both, from a conceptual point of view, related to post-grant amendment of statutory rights, differences between patent and trade mark amendment practices were probably not even noticed.  This is only natural.  We now think of "intellectual property" as a single body of legal practice with many branches and we therefore look to similarities -- but look how little cross-reference was made between different IP rights before the 1980s.  The various IP rights had their own rules relating to availability and recovery of damages, allocation as between employer and employee, making of groundless threats and so on.

Merpel says, the real reason why amendment happens early for patents and late for trade marks is that patents are big, powerful but short-lived beasts while trade marks have far less clout when it comes to keeping competitors' goods off the market but they drag on forever.

What do readers think? And let's hear from readers outside the UK too!