[ipv6-wg] Latest draft for RIPE554-bis confusion with MUST and SHOULD

Hey everyone,

I am a bit confused/worried about section 5 (Requirements for IPv6 
support in software). There is a list, of what a developer/vendor MUST 
(at a minimum) support.
However, the list contains multiple bullet points that include words 
that make them seem optional (like "something SHOULD be supported" or 
"it's recommended").
I don't have any experience with the creation of RFC and just joined 
this mailing list to be able to see what you are doing here out of 
interest, so I think this might be (at least partly) intended, as some 
of these bullet points seem to have been copied from other sources 
(e.g., https://www.ripe.net/publications/docs/ripe-554 contains this 
first bullet point with "recommended").
However, I think the standard should make sense on its own and therefore 
don't think that this is a valid justification. Things should be clearly 
marked as either mandatory or optional.

Therefore, I would suggest rephrasing the introduction sentence from
     Software developer/vendor must at a minimum do the following things 
to guarantee this:
to
     [A] software developer/vendor should at a minimum do the following 
things to guarantee this:

However, in case some things in the list should be mandatory and some 
optional, I think it might make even more sense to split the list in an 
optional and a mandatory list.

If all the things in the list are actually mandatory, I would propose 
the following changes to the bullet points:

 From
     It is strongly recommended not to use any address literals in 
software code, as described in “Default Address Selection for Internet 
Protocol version 6” [RFC6724]
to
     Address literals must not be used in software code, as described in 
“Default Address Selection for Internet Protocol version 6” [RFC6724]

 From
     Every place where IPv6 addresses are shown or output the notation as 
specified in "A Recommendation for IPv6 Address Text Representation 
[RFC5952]" should be followed
to
     Every place where IPv6 addresses are shown or output[,] the notation 
as specified in "A Recommendation for IPv6 Address Text Representation 
[RFC5952]" must be followed

 From
     When setting up a connection the software should follow Default 
Address Selection for Internet Protocol Version 6 [RFC6724] or Happy 
Eyeballs Version 2: Better Connectivity Using Concurrency [RFC8305]
to
     When setting up a connection[,] the software must follow Default 
Address Selection for Internet Protocol Version 6 [RFC6724] or Happy 
Eyeballs Version 2: Better Connectivity Using Concurrency [RFC8305]

 From
     These requirements should also be checked in any library or tools 
used by the software
to
     These requirements must also be checked in any library or tools used 
by the software


I'm not particular interested in what wording exactly is used, these are 
just some suggestions.
Please feel free to let me know what you think.

Lorenz