[seb1204]

Yes, except there seems to be a move on the best words from SHALL to MUST and from SHOULD to MAY. IANAL but I recall reading this in e.g. legal language guidance sites.

[aunderscored]

RFC language is expmicltly defined in 2119[0]. Any other interpretation is incorrect.

[0] https://www.rfc-editor.org/rfc/rfc2119

[Alive-in-2025]

Thank you for that. So should is optional, people!