Honest question: why is anything that is patented ever made to be part of a standard?
[0] https://books.google.com/books?id=qTkEAAAAMBAJ&lpg=PA52&ots=....
[1] https://books.google.com/books?id=OFCXnqlSFKwC&lpg=PA709&dq=....
[2] https://www.ftc.gov/news-events/press-releases/2008/01/ftc-c....
Edited to fix formatting
The correct links are below.
[0] https://books.google.com/books?id=qTkEAAAAMBAJ&lpg=PA52&ots=...
[1] https://books.google.com/books?id=OFCXnqlSFKwC&lpg=PA709&dq=...
[2] https://www.ftc.gov/news-events/press-releases/2008/01/ftc-c...
a) The people making the standard work for the companies filing the patents. They are highly incentivized to make their own patents required, and
b) There's all sorts of potential legal liability associated with just knowing about patents, much less telling anyone else or writing that knowledge down.
As a result, you get things like the ISO and ITU IPR policies which profess to make the standardization process "patent blind". That is, so long as you agree to license your patents under FRAND terms, you can participate, and no one is allowed to exclude your technology solely on the basis of your patents.
This results in maximally patented standards. Even if you're not interested in seeking rent from other standards users, lots of other people contributing to the standard are. So you're forced to file patents just to minimize the amount you have to pay to use the technology you yourself helped create.
That's why you see things like the HEVC mess, where four years after the standard was completed, no one knows if it's even possible to license all of the patents required, nor how much it would cost if you could.
ISO/IEC and ITU have had a common patent policy since at least 2006. Here is their "Patent Statement and Licensing Declaration" form: https://www.itu.int/dms_pub/itu-t/oth/04/04/T04040000020004P...
On page 3, where the space for entering patent numbers is, it says they are "desired but not required for options 1 [royalty-free] and 2 [FRAND]; required in ITU for option 3 [refusal to commit to either of those licensing terms]". ISO actually allows you to claim you have patents on a standard, refuse to license them to anyone at any price, and not even tell anyone what the patents are, much less which part of the standard they cover. This has happened to at least one standard that was attempting to be royalty-free.
In general, you can assume the answer to the question, "Does the proponent of this technology have patents covering it?" is yes, for the reasons I outlined in the GP. So in practice the above disclosures provide nearly zero information. They don't help you evaluate alternative designs, because you don't know what you need to change to avoid the patents. You also don't know when one party might have patents on a contribution made by a different party [1]. The disclosure is at the level of the standard as a whole, and not by individual feature.
The disclosures are also not very specific about the actual licensing terms. I've had an expert lawyer who made her career on dealing with patent licensing tell me with a straight face that she had no idea what FRAND means. In some industries, it is common practice to require someone to sign an NDA before you will even tell them what your supposedly "non-discriminatory" terms are.
The actual licensing terms are negotiated well after the standard is complete, by which point it is too late to solve problems by excluding technology.
[1] This is quite common. People read the contributions of others and rush to file something based on the direction they think it is going. That ensures they have patents on the standard regardless of whether or not any of their own contributions make it in.
So you can discuss it openly with your competitors and suppliers without running afoul of anti-trust laws. I also assume it's the major reason for organizations like ISO to exist in the first place.