On Topic-Based Subscription Components page:

• https://build.fhir.org/ig/HL7/fhir-subscription-backport-ig/components.html#subscriptions-and-fhir-versions
  In the statement “Servers SHALL look for this parameter during subscription negotiation and SHALL not accept requests for notification …”, "SHALL not" needs to be updated to “SHALL NOT”

On Payload Types page:

• https://build.fhir.org/ig/HL7/fhir-subscription-backport-ig/payloads.html#empty 
  In the statement “When the client receives a notification of this type, it may query the server to fetch all the relevant resources based on the SubscriptionTopic and applicable filters.”  The word “may” needs to be “MAY” to represent conformance language
• https://build.fhir.org/ig/HL7/fhir-subscription-backport-ig/payloads.html#empty 
  In the statement “When the content type is empty, notification bundles SHALL not contain Bundle.entry elements other than the SubscriptionStatus for the notification.”, "SHALL not" needs to be updated to “SHALL NOT" to represent conformance language
• https://build.fhir.org/ig/HL7/fhir-subscription-backport-ig/payloads.html#full-resource
  In the statement “From a security perspective, full-resource payloads should only be used when the channel is secure - notifications will contain PHI.” ‘should’ needs to be ‘SHOULD’ to represent conformance language.

On Handling Errors page:

• https://build.fhir.org/ig/HL7/fhir-subscription-backport-ig/errors.html#recovering-from-errors
  In the statement “Once an application has returned to a functional state, it should request the subscription is reactivated by updating the status to either requested or active as appropriate.” ‘should’ needs to be ‘SHOULD’ to represent conformance language.