Which aerodromes are in the scope of ICAO recommendations? I'm looking for a clarification of how aerodrome characteristics are regulated in a country which has signed the ICAO Chicago Convention (more on Wikipedia). To guide the answer, I'm providing a list of ICAO statements, which may be ignored if non pertinent. The question follows this list.

ICAO statements


Under this convention, State members participating to international air travel agreed to follow ICAO recommendations and best practices:



  Article 12: Each contracting State undertakes to keep its 
  own regulations in these
  respects uniform, to the greatest possible extent, with those
  established from time to time under this Convention. Over the high
  seas, the rules in force shall be those established under this
  Convention. Each contracting State undertakes to insure the
  prosecution of all persons violating the regulations applicable.

The States also agree to provide some infrastructure:



  Article 18: Each contracting State undertakes, so far as it may find
  practicable,
  to: a) Provide, in its territory, airports, radio services,
  meteorological services and other air navigation facilities to
  facilitate international air navigation, in accordance with the
  standards and practices recommended or established from time to time,
  pursuant to this Convention.

Nineteen annexes describe SARPs, standards and recommended practices. Annex 14 (volume 1) describes aerodromes. Applicability is defined in § 1.2:



  1.2.2 The specifications, unless otherwise indicated in a particular context, shall apply to all aerodromes open to public use in
  accordance with the requirements of Article 15 of the Convention.

Article 15:



  Every airport in a contracting State which is open to public use by
  its national aircraft shall likewise, subject to the provisions of
  Article 68, be open under uniform conditions to the aircraft of all
  the other contracting States.

Article 68:



  Each contracting State may, subject to the provisions of this
  Convention, designate the route to be followed within its territory by
  any international air service and the airports which any such service
  may use.

Each State member also publishes aeronautical information (AIP), described in Annex 15 to the convention:



  2.1.1 Each Contracting State shall: a) provide an aeronautical information service (AIS); or b) agree with one or more other
  Contracting State(s) for the provision of a joint service; or c)
  delegate the authority for the provision of the service to a
  non-governmental agency, provided the Standards and Recommended
  Practices of this Annex are adequately met.

Each State must list in the AIP the deviation from ICAO SARPs, in section GEN:



  4.1.1.1 c: a list of significant differences between the national regulations and practices of the State and the related ICAO Standards,
  Recommended Practices and Procedures, given in a form that would
  enable a user to differentiate readily between the requirements of the
  State and the related ICAO provisions;



From the statements listed, it's not clear if all aerodromes open to the public are in the scope of ICAO recommendations and SARPs. This may be only those open to international travel, there is some ambiguity.

Question

How do I know whether such aerodrome in a given country benefit from ICAO recommendations as included in the national regulations. For example, there is this recommendation (annex 14):


  3.9.6 Recommendation.— To facilitate the movement of aeroplanes,
  fillets should be provided at junctions and intersections of taxiways
  with runways, aprons and other taxiways. The design of the fillets
  should ensure that the minimum wheel clearances specified in 3.9.3 are
  maintained when aeroplanes are manoeuvring through the junctions or
  intersections.


How does that apply to aerodromes in Germany or in Canada for instance?
Which aerodromes are in the scope of ICAO recommendations?

Per Annex 14, international airports only, and preferably any public use airport—


  1.3.1 As of 27 November 2003, States shall certify aerodromes used for international operations in accordance with the specifications contained in this Annex as well as other relevant ICAO specifications through an appropriate regulatory framework.
  
  1.3.2 Recommendation.— States should certify aerodromes open to public use in accordance with these specifications as well as other relevant ICAO specifications through an appropriate regulatory framework.


(Emphasis not mine.)



If for any reason, a country deviates from the standards, it needs to notify ICAO.

How do I know whether such aerodrome in a given country benefit from ICAO recommendations?

Deviations are published by ICAO in Supplements to each Annex. I can't speak for 3.9.6 due to paywalls. However, here are examples for Canada's deviations to Annex 14—


  
  Canada does not provide runway end safety areas but does provide a 60 m graded strip beyond the runway end. (More on that story.)
  Canada computes runway longitudinal slopes by dividing the difference between the maximum and minimum runway end elevation by the runway length.
  


Below (may not be current due to paywalls) are countries that fully adhere to Annex 14—


  Contracting States which have notified ICAO that no differences exist:
  
  
  Colombia
  Egypt
  Georgia
  Ghana
  Ireland
  Malaysia
  Monaco
  Namibia
  Peru
  Sri Lanka
  United Republic of Tanzania