J. Mc Laughlin wrote:
Submarine patents have gone away with a change in the maximum duration of a
patent being measured from the date of filing (and not the date of issue).
Additionally, almost all applications are published 1.5 years after filing.
Can not hide.
73, Mac N8TT


Gone mostly away, I'd say...
There is an "art" in the writing of disclosures and claims that cause
the patent to not look applicable. I knew someone who patented
everything using the word "Catalyst" in the title, etc. There are
thousands and thousands of catalyst patents issued all the time, so
yours would be lost in the morass, and nobody has the time to read ALL
the patents.

Modern search engines help a lot to fight this.

There's also the fact that standards bodies are much better about making
participants in a standards setting process disclose their "patents in
waiting" so you don't get submarined by adopting a standard, only to
find the next year that it requires a license from some patent holder.