Why does EASA publish some foreign ADs with a prefix (e.g. US-, BR-, RU- )?
This is a practical IT solution only and it is not meant to be read as a different or new AD number. Some foreign ADs follow the same AD numbering principle (YYYY-XX-XX), which can result in identical numbers for two ADs issued by two different Authorities. In past cases, the AD Publishing Tool mixed up the two records and file uploads were corrupted. The prefix was therefore introduced to clearly distinguish those ADs. The AD number as identified within the AD document itself applies and there is no requirement to record compliance using the AD number with the prefix.