FHIR specification is being adopted in Canada.
The base FHIR specification (this specification) describes a set of base resources, frameworks and APIs that are used in many different contexts in healthcare. However there is wide variability between jurisdictions and across the healthcare ecosystem around practices, requirements, regulations, education and what actions are feasible and/or beneficial.
An Implementation Guide is a collection of Profiles, that make conformance rules (technially, Conformance, StructureDefinition, ValueSet, etc.) that, together with textual guidance, provides instruction on how to make use of FHIR in a particular problem space. Implementation guides may be developed and published as part of a FHIR release or as separate specifications. Additional support and tooling for implementation guides is being developed, so the content provided here should be considered "preliminary" from a publication perspective.
The implementation guides include artifacts with a set of representations generated from the conformance resources. All the representation forms are equally normative. Many examples are also provided, and considerable care is taken over them. However, unless indicated otherwise, the examples have no formal standing (see General Notes about examples).
Note: At present, some implementation guides are published in conjunction with the FHIR specification because tooling that supports straightforward independent publication is not yet developed. However, the intention is that in the future implementation guides will be published separately from the core FHIR specification. The various implementation guides are subject to separate ballots than the core FHIR specification. There is a registry of additional implementation guides 
.
The predominance of US implementation guides in this specification is a reflection of the current point in the lifecycle of standards development for the US program. It should in no way be interpreted as suggesting that FHIR is a US-centric specification.