RFC-2026, section 4.1.2 ("Draft Standard"):
If patented or otherwise controlled technology is required for
implementation, the separate implementations must also have resulted
from separate exercise of the licensing process.
The problem is that very few standards make it to Draft. As the old saw
goes, "the Internet is running on proposed standards". (A more accurate
description would be "on Internet drafts and proposed standards").
Statistical details were presented at the last plenary.
Thus, this mechanism offers almost no remedy or protection. It would
also be interesting to know if this has ever been checked in reality,
even for the few standards that have made it that far. Also, this does
not help if the two licensing arrangements are between two big
corporations that have blanket mutual licensing deals, as is common.
This says very little about whether a smaller company, a competitor or
an open-source implementation could get a license.