There seems to be a lot of confusion about the role of ICAO in aviation regulations. Maybe this is largely caused by a large portion of the community being from the US? Although the US is an ICAO member state, the FAA tends to prefer making their own rules, rather than adopting ICAO Standards and Recommended Practises.
I thought I might clear up some confusion by simply quoting the Wikipedia page (emphasis mine):
Standards And Recommended Practices (SARPs) are technical specifications adopted by the Council of ICAO in accordance with Article 37 of the Convention on International Civil Aviation in order to achieve "the highest practicable degree of uniformity in regulations, standards, procedures and organization in relation to aircraft, personnel, airways and auxiliary services in all matters in which such uniformity will facilitate and improve air navigation".
SARPs are published by ICAO in the form of Annexes to Chicago Convention. SARPs do not have the same legal binding force as the Convention itself, because Annexes are not international treaties. Moreover States agreed to "undertake to collaborate in securing (...) uniformity", not to "comply with". Each Contracting State may notify the ICAO Council of differences between SARPs and its own regulations and practices. Those differences are published in the form of Supplements to Annexes.
A Standard is defined by ICAO as "any specification for physical characteristics, configuration, material, performance, personnel or procedure, the uniform application of which is recognized as necessary for the safety or regularity of international air navigation and to which Contracting States will conform in accordance with the Convention".
A Recommended Practice is defined by ICAO as "any specification for physical characteristics, configuration, material, performance, personnel or procedure, the uniform application of which is recognized as desirable in the interest of safety, regularity or efficiency of international air navigation and to which Contracting States will endeavour to conform in accordance with the Convention".
A common misunderstanding seems to be that anything contained in the ICAO annexes are simply recommendations that countries can pick and choose from as they so desire. However, ICAO states are actually expected to follow the Standards and Recommended Practises, and will publish a list of differences between national regulations and ICAO SARPs. Even the US has such a list (it is remarkably long, too).
I suggest the following:
Instead of phrasing questions and answers like ICAO SARPs are less "correct" or "important" than, say, FAA regulations, I recommend that we realise, that the ICAO SARPs do in fact form the background for most aviation regulations in the world - even if the SARPs themselves are not legally binding.
I also suggest that the weird icao-recommendations tag is replaced by the icao-sarps tag - or just use the simple icao tag. If a question is specifically about ICAO Recommended Practises, the icao-recommendations tag could still be used - but in that case we need a separate icao-standards tag as well.