No, that ALSO applies to patents, though the term is actually 6 years rather than the standard 3. Your 'confused' comment is a good example of why the FSF should encourage educating ones-self instead of trying to play semantic games with the english language.

I assume you are talking about this, which mentions a 6 year limit:

https://www.law.cornell.edu/uscode/text/35/286

But that only limits the time period for which damages may be claimed - it does not forfeit the ability to claim damages altogether, which is what may happen with trademarks; that's a pretty significant difference.

Ok, that is an interesting aspect of US patent law I wasn't familiar with. But this doesn't look like a universal property of patents, more likely it's specific to the US?